1. P=3x+3y

A triangle is shown with 3 sides. On two of the sides it shows x+y. So it asks to find the measure of the third side of the triangle. P is the measure of the perimeter. Show all work.

2. P=7x+2y

A triangle is shown with 3 sides. On one side, it says 2x+y. On the other, it says 3x-5y.

So the sum of two sides are 2x+2y and the perimeter is 3x+3y. So if we subtract the two sides from the perimeter we will have the dimension of the final side ...

3x+3y-2x-2y=x+y which is the same as the other two sides, thus this is an equilateral triangle.

...

Again we will subtract the sum of two sides from the perimeter to find the measure of the third side ...

7x+2y-2x-y-3x+5y

2x+6y is the third side ...