Find the tenth term in the sequence
that is defined as follows:
an = 4+ (-1)

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 am not sure :

step-by-step explanation: