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

Part 1)
`y=x+21.5`

Part 2)
`y=x+18`

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=(y2-y1)/(x2-x1)`

take two points from the table

(2,23.5) and (4,25.5)

substitute in the formula

`m=(25.5-23.5)/(4-2)`

`m=(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=(y2-y1)/(x2-x1)`

take two points from the table

(2,20) and (4,22)

substitute in the formula

`m=(22-20)/(4-2)`

`m=(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`