Question

Write a linear equation that represents the cost of buying t-shirts from Paula's printing. identify the meaning of each variable in your equation.
write a linear equation that represents the cost of buying t-shirts from shantay's shirts. identify the meaning of each variable in your equation.​

Answer 1

Answer:

Part 1) $y=x+21.5$

Part 2) $y=x+18$

Step-by-step explanation:

Part 1) Write a linear equation that represents the cost of buying t-shirts from Paula's printing.

Let

x ----> the number of t-shirts

y ----> the cost in dollars

step 1

Find the slope

The formula to calculate the slope between two points is equal to

$m=\frac{y2-y1}{x2-x1}$

take two points from the table

(2,23.5) and (4,25.5)

substitute in the formula

$m=\frac{25.5-23.5}{4-2}$

$m=\frac{2}{2}=1$

step 2

Find the equation of the line in point slope form

$y-y1=m(x-x1)$

we have

$m=1$

$(x1,y1)=(2,23.5)$

substitute

$y-23.5=(1)(x-2)$

Convert to slope intercept form

$y=mx+b$

$y=x-2+23.5$

$y=x+21.5$

Part 2) Write a linear equation that represents the cost of buying t-shirts from Shantay's shirts.

Let

x ----> the number of t-shirts

y ----> the cost in dollars

step 1

Find the slope

The formula to calculate the slope between two points is equal to

$m=\frac{y2-y1}{x2-x1}$

take two points from the table

(2,20) and (4,22)

substitute in the formula

$m=\frac{22-20}{4-2}$

$m=\frac{2}{2}=1$

step 2

Find the equation of the line in point slope form

$y-y1=m(x-x1)$

we have

$m=1$

$(x1,y1)=(2,20)$

substitute

$y-20=(1)(x-2)$

Convert to slope intercept form

$y=mx+b$

$y=x-2+20$

$y=x+18$