find the real solution of p^3+4p^2-9p=36

Question

please help me find the answer to this and show work. thanks

Answer 1

Given polynomial is p^3+4p^2-9p = 36

Subtract 36 from each side.

p^3+4p^2-9p-36 = 36-36

p^3+4p^2-9p-36 = 0

p^2(p+4)-9(p+4) = 0

(p^2-9)(p+4) = 0

p^2-9 = 0                      and       p+4 = 0

Add 9 to each side                    Subtract 4 from each side.

p^2-9+9 = 0-9                          p+4-4 = 0-4

p^2 = 9                                           p = -4   

p = ±3    and   p = -4

Real solution of given polynomial is p = ±3,-4