What is the additive inverse of 6x – 21?

Answer this question, only if you know the answer. 30 points and brainliest!

Trish receives $450 on the first of each month. josh receives $450 on the last day of each month. both trish and josh will receive payments for next four years. at a discount rate of 9.5 percent, what is the difference in the present value of these two sets of payments?

The parabola x = y² - 9 opens: a.)up b.)down c.) right d.)left