Asked by Anonymous

Expand and simplify (p+3)(p-7)
Answered by Reiny
You should learn to do this until you can do it in one step, it is essential to know.

(p+3)(p-7)
= p^2 - 7p + 3p - 21
= p^2 - 4p - 21

with practice you can get to the last line in one step