If the sum is 12 and one addend is 4, what is the other
addend?

The other is 8. An addend is a number which is added to another. If 4 is one of them, and the sum is 12, 12-4 is 8.

The vertex of the quadratic function is (1.5, -.75)

I'll do the first one for you. it isn't very hard at all.on number one, you have (50 × 3), which equals 150, and (3 × 3), which equals 9. after you establish that, you add 150 and 9 together. so, (150 + 9) equals 159.this means that 53 × 3 = 159.