The answer to this question would b:
=5x−9
Let's assume
number of shorts is x
we are given
People bought 2 times as many T-shirts as shorts
so, number of T-shirts is 2*x=2x
Dots sells T-shirts ($3) and shorts ($7)
so, total price of T-shirts 
so, total price of shorts 
now, we are given
total sales were $520
so,
total price of T-shirts+total price of shorts = total sales
we will get equation

now, we can solve for x


so,
number of shorts is 40
number of T-shirts is 2*40=80............Answer
First find out the triangle (red) in the top left.

The area of a triangle is found by length times width and divide it all by 2 because a triangle is half of a square. Now we multiply that by 2 for the second triangle (in green) at the bottom. We can do this because the blue does to the half way mark on the quilt so the other triangle on the bottom has to be the same.

Now we find out the area of the whole SQUARE quilt. It already gave the measurement of one side so they all have to be the same.

Now we only need the area of the side the blue is on. So divide by 2 and get 72.
Now subtract 18 from 72.
The answer is 54 for blue.