Estimation Rita goes to the mall. If x is the number of items she ​bought, the expression 18.54x+23 gives the amount she spent in dollars at one store. Then she spent 25 dollars at another store. Find the expression which represents the amount Rita spent at the mall. Then estimate how much Rita spent if she bought 2 items.

Answers

Answer 1

Answer:

18.54x +48$85

Step-by-step explanation:

The total amount Rita spent is ...

  (18.54x +23) +(25) = 18.54x +48 . . . total spent

__

When x=2, that is approximately ...

  (18.5)(2) + 48 = 37 +48 = (40 -3) +(50 -2) = (40 +50) -(3 +2) = 90 -5 = 85

Rita spent about $85 if she bought 2 items.

_____

Additional comment

Estimation is often done using 1 significant figure. In this case, that would mean rounding the equation to 20x+50, so it would give a value of 90 when x=2.

An additional task when estimating is to estimate the error in the estimate. Here, using 20x+50 has an error of approximately 1.5x+2 (too high), so the error for 2 items will be about (1.5(2)+2) = 5. That is, the estimate of 90 is approximately 5 too high. Even this estimate has a remaining small error of 0.04x (too low).


Related Questions

The polygons in each pair are similar. find the missing side length​

Answers

If polygons are similar ratio of sides will be same

[tex]\\ \sf\longmapsto \frac{6}{14} = \frac{3}{x} \\ \\ \sf\longmapsto 6x = 14 \times 3 \\ \\ \sf\longmapsto 6x = 42 \\ \\ \sf\longmapsto x = \frac{42}{6} \\ \\ \sf\longmapsto x = 7[/tex]

Which of the following equations has roots r = -1, x = -2, and x = 3i?

Answers

Option A. has roots of x=-1,-2, and 3i

Find the measure of GH. PLEASE HELP ASAP!!
A. 12
B. 10
C. 11
D. 7

Answers

Answer:

10 is the correct answer.

Answer:

10

Step-by-step explanation:

Answer the following (a) find an angle between 0 and 2 that is coterminal with 27/10 (b) find an angle between 0 and 360 That is conterminous with 775

Answers

Answer:

I have no clue sorry my bad bro

Describe how to determine the average rate of change between x = 4 and x = 6 for the function f(x) = 2x3 + 4. Include the average rate of change in your answer.

Answers

Answer:

152

ΔY =  436 - 132 =304

Δ X = 6-4 = 2

ΔY/X = 304/2 = 152

Step-by-step explanation:

What is the percent increase each year for the investment?

Answers

Answer:

11.5%.

Step-by-step explanation:

Looking at the base of the exponent, it can be seen that it is 1.115. 1.00 is equal to 100% of the investment value each year. There is an additional 0.115, which is equivalent to 11.5%, which represents the increase in the investment value each year.

Therefore, the percent increase each year for the investment is 11.5%.

9. An equation representing the height of a burning candle is H = 2(9 - 2t), where
H is the height of the candle in cm and
t is the amount of time that the candle has been burning in minutes.
How long will it take for the candle to burn down to a height of 4 cm?
a. 2 min
b. 3.5 min
C. 5.5 min
d. 7 min

Answers

Answer:

H= 4cm

we want t

4=2(9-2t)

2=(9-2t)

-7=-2t

t=3.5 minutes

A rectangle with an area of 3990 cm2 is x centimeters wide and (x+4) centimeters long. To the nearest tenth of a centimeter, the width and length are

Answers

Answer: width:60.2 cm

Length: 64.2 cm

Step-by-step explanation:

Given

The area of the rectangle is [tex]3990\ cm^2[/tex]

Width of the rectangle is [tex]x\ cm[/tex]

Length of the rectangle is [tex]x+4\ cm[/tex]

Area of the rectangle is the product of length and width

[tex]\therefore 3990=(x+4)x\\\Rightarrow 3990=x^2+4x\\\Rightarrow x^2+4x-3990=0\\\Rightarrow x=60.198\ or\ -65.198\ cm\\\text{Neglecting negative term}\\\Rightarrow x=60.198\approx 60.2\ cm[/tex]

Width of the rectangle is [tex]60.2\ cm[/tex]

Length of the rectangle is [tex]60.2+4=64.2\ cm[/tex]

Find the value of ‘m’ in 3m+12=15​

Answers

[tex] \sf3m + 12 = 15 \\ \sf3m = 15 - 12 \\ \sf3m = 3 \\ \sf \: m = \frac{3}{3} \\ \sf \: m \: = \underline{ \bf \: 1}[/tex]

-> Just move all the numbers from the left side to the right side until only the variable is left. Then you can solve the equation & find the required value.

3 m+ 12 = 15

⇔3 m=  3

⇔m=  1

Select the equation written in slope intercept form that corresponds to the given slope y intercept

Answers

Answer:

[tex]y = -6x + 1[/tex]

[tex]y = 6x - 2[/tex]

[tex]y = -2x + 4[/tex]

[tex]y = x + 6[/tex]

Step-by-step explanation:

Given

See comment for missing part of the question

Required

The equation in slope intercept form

A linear equation is of the form:

[tex]y = mx + b[/tex]

(a) m = -6, b =1

Using the above format, we have:

[tex]y = -6x + 1[/tex]

(b) m =6, b = -2

[tex]y = 6x - 2[/tex]

(c) m = -2, b = 4

[tex]y = -2x + 4[/tex]

(d) m = 1, b = 6

[tex]y = x + 6[/tex]

For which of following equations is (-2,-3) not a solution (Will give brainlest plus 33 points)

Answers

Answer:

[tex] - 3x = 4y - 6[/tex]

[tex] - 3( - 2) = 4( - 3) - 6[/tex]

[tex]6 = - 12 - 6[/tex]

[tex]6 = - 18[/tex]

How many sides does a regular polygon with 45° exterior angles have?
Numerical answer only.

Answers

Answer:

8 sides (octagon)

Step-by-step explanation:

sum of exterior angles is always 360º

360 / 45 = 8 sides

Answer:

8 sides

Step-by-step explanation:

If all the angles of the polygon are the same, divide the angle by 360 and u get the answer.

Use the circle to represent the following situation and show how you came up with the answer.

For lunch, you stop at a Pizza Express, where they sell pizza whole or by the slice. The area of one slice of a 16" pizza is 33.49in².
What angle does one slice make?

Answers

Answer:

look below bestie

Step-by-step explanation:

ok so i dont know most of it (sryy) but the area of the entire pizza is 535.84in², the radius of the pizza is about 13.05 and yea. thats all i got

if a number is added to 3, the result is 10 find the number​

Answers

Answer:

7

Step-by-step explanation:

10 minus 3 will give you the number

Answer:

7

Step-by-step explanation:

let the number added to 3 be 'x'

we know;

X+3=10

X=10-3

X=7


The shaded sector of the circle shown above has an area of 18 pi square feet

Answers

Answer:

F

Step-by-step explanation:

Area of sector=pi*r^2*(theta/360) = pi*r^2*(45/360)

18*pi=pi*r^2*(1/8), r=12. Circumference is 24*pi

ANSWER PLEASE
simplify 2n(n2+2n+3)-3(2n+7) and (-4n2-3n-8)+2(n+9)

Answers

Step-by-step explanation:

> 2n³+4²+6n-6n-21

2n³+4n²-21

> -4n²-3n-8+2n+18

-4n²-3n-8+2n+18

-4n²-n-8+18

-4n²-n+10

What are factorials? And how do you do them in fractions like
4!5!
——- How do you do that question? And why do you leave
6! The 5! without anything, like why does it not go like
(5)(4)(3)(2)(1)? Why is it like that?

Answers

I think that it is 54

Please help me with this anyone please and thank you

Answers

Answer:

w∈ {-1/5, -5/3]

If this is what you were looking for...

Find the real or imaginary solutions by factoring.
X^4 -3x^2 = -2x^2

Answers

Look in the images it is solved.

The volume of a one is 80 cubic cm what is the volume of the cylinder with the same base and height of the cone

Answers

Answer:

240 cubic cm

Step-by-step explanation:

Volume of a cone = 1/3(nr^2h)

volume of a cylinder = nr^2h

n = 22/7

r = radius

The volume of a cone is 1/3 that of a cylinder

to determine the volume of the cylinder with the same parameters as a cylinder, multiply the volume of the cone by 3

80 x 3 = 240 cubic cm

find the distance traveled in 27.9 minutes

Answers

Answer:

A

Step-by-step explanation:

d = 0.5 * t    There are no conversions. You just substitute the value for t.

d = 0.5 * 27.9

d = 13.95 which is A

Solve the following equation using
distribution.
2 (4x – 12) = 5
(3) (4x) – (*) (12) = 5
2x - 6 = 5
+6
+6
2x = 11
.. i need help asap look at pics please i need this class done completely in two hours

Answers

Answer: 5.5

Step-by-step explanation: It is basically already solved the only thing I did was isolate x by itself my moving the 2 over and doing 11 divided by 2 which equals 5.5. This means that x equals 5.5

What does z represent

Answers

Answer:

not sure what your asking.... is there a file you can submit?

Step-by-step explanation:

find the missing side.​

Answers

Answer:

33.4

Step-by-step explanation:

tan50 = x/28

x =28tan50 = 33.3691 = 33.4 (nearest tenth)

Evaluate 1/243 ( base must be 1/9)




PLEASE I NEED THIS FAST!

Answers

Answer:

(1/9)^2 x 1/3

Step-by-step explanation:

1/243

=> 1 / 3 x 3 x 3 x 3 x 3

=> 1 / 9 x 9 x 3

=> (1/9)^2 x 1/3

what does it mean when x is a constant, in a maths equation

Answers

Answer: a constant is a fixed number in an expression. For example x+5=9. The constants are 5 and 9 since it’s a fixed number. Since it says x is a constant it means it can only be one answer.

x + y = −3
y = 2x + 2

Answers

Answer:

Step-by-step explanation:

x + y = −3

y = 2x + 2

Substitute the y value of the second equation into the top equation

x + 2x + 2 = - 3

3x + 2 = - 3

3x = -3 -2

3x = - 5

x = -5/3

x + y = - 3

-5/3 + y = - 3

y = -3 + 5/3

y = -1 1/3

Find the slope of the line that passes through (23, -30) and (-7, 18).

Answers

Answer:

slope = - [tex]\frac{8}{5}[/tex]

Step-by-step explanation:

Calculate the slope m using the slope formula

m = [tex]\frac{y_{2}-y_{1} }{x_{2}-x_{1} }[/tex]

with (x₁, y₁ ) = (23, - 30) and (x₂, y₂ ) = (- 7, 18)

m = [tex]\frac{18-(-30)}{-7-23}[/tex] = [tex]\frac{18+30}{-30}[/tex] = [tex]\frac{48}{-30}[/tex] = - [tex]\frac{8}{5}[/tex]

Evaluate (mm)(x) for x=-3

Answers

Step-by-step explanation:

Maybe

(m²)(-3)

-3m²

hope it helps

A science teacher wrote the table of values below.

Amount of Hydrogen vs. pH
Amount of Hydrogen, x
(in moles per liter)
pH, f(x)
One-tenth
1
StartFraction 1 Over 100 EndFraction
2
StartFraction 1 Over 1000 EndFraction
3
StartFraction 1 Over 10,000 EndFraction
4
StartFraction 1 Over 100,000 EndFraction
5

Which function models the data in the table?
f (x) = StartFraction 1 Over x EndFraction, x not-equals 0
f (x) = log StartFraction 1 Over x squared EndFraction, x not-equals 0
f (x) = log StartFraction 1 Over x EndFraction, x not-equals 0
f (x) = StartFraction 1 Over x squared EndFraction, x not-equals 0

Answers

The best function that models the data is f(x) = log StartFraction 1 Over x EndFraction, x not-equals 0

Find the table attached below

From the table shown,  we can see that when   x = 1/10, f(x) = 1

Similarly when x = 1/100, f(x) = 2

According to the law of logarithm, we can say that:

Log 10 = 1

Log 100 = 2 etc..

Recall that f(x) = 1 when x = 1/10, this means that;

F(x) = log 10

F(x) = log(1/1/10))

F(x) = log(1/x) since x = 1/10

Similarly if f(x) = 2 when x = 1/100

F(x) = log 100

F(x) = log(1/1/100))

F(x) = log(1/x) since x = 1/100 in this case

On a general note, we can conclude that f(x) = 1/x where x is not equal to zero.

Learn more function models at https://brainly.com/question/11989600

Answer:

A

Step-by-step explanation:

The person above said so

f (x) = StartFraction 1 Over x EndFraction, x not-equals 0

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