Well, in order to prove the Pythagorean theorem, every triangle you are using has to have one right angle (90-degree angle), and the side opposite to it will be called the hypothenuse. The remaining two triangles will be acute angles (<90 degrees), and the sides opposite to them are called sides/catheti.
I think I believe it’s 8000
Her friends drink 5/24 gallons of lemonade. (I hope I'm right)
Use Subtraction
1. Subtract
x+2y=7
3x-2y=-3
-------------
4x+0y=4 SIMPLIFY 4x=4
2. DIVIDE
4x=4
x=1
Substitute that into either of the original equations to get x=1, y=3