Can someone me out with this? ? i am god awful at basic math such as if i sound absurdly stupid; ;

For graphs, always start with line x then do line y.

the sum of all the angles in a triangle are equal to 180

so you can add   the 3 given angles together to equal 180:

5y + 2y + 2y = 180

or since all three angles have the same letter, combine the 3 angles to equal 180:

9y = 180