Answer:
[tex]y=21.50x[/tex]
Step-by-step explanation:
Let
x ----> the number of t-shirts
y ----> the cost of buying T-shirts from Paula’s Printing in dollars
take two points from the given data
we have
(2,43) and (4,86)
step 1
Find the slope
The formula to calculate the slope between two points is equal to
[tex]m=\frac{y2-y1}{x2-x1}[/tex]
substitute the values in the formula
[tex]m=\frac{86-43}{4-2}[/tex]
[tex]m=\frac{43}{2}=\$21.50\ per\ t-shirt[/tex]
step 2
Find the equation of the line in point slope form
[tex]y-y1=m(x-x1)[/tex]
we have
[tex]m=21.50[/tex]
[tex](x1,y1)=(2,43)[/tex]
substitute
[tex]y-43=21.50(x-2)[/tex]
step 3
Convert to slope intercept form
[tex]y=mx+b[/tex]
Isolate the variable y
[tex]y-43=21.50x-43[/tex]
[tex]y=21.50x-43+43[/tex]
[tex]y=21.50x[/tex]
This linear equation represent a proportional relationship (the line passes through the origin)
