1. If you're trying to gain access to a credit card before you turn 21, which of the suggestions rely on the support of your parent or guardian?

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

i hope this is what you were looking for.

see attached graph