All sides are the same, hence, all three angles are the same, and each one of them is 60 degrees. Due to that:
7x + 4 = 60
7x = 56
x = 56/7 = 8
8y + 12 = 60
8y = 48
y = 48/8 = 6
I think you can multiply how many are defective in a sample by how much more stuff there is
The solutions are where these two functions intersect, that is, at x = -4 and x = -6. The answer is C.