Values for linear system

Plug the x for each linear multiplybut the other one is to distribute it so 3(x+2)=0

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