(1)

use identity

see spoiler if stuck

Spoiler:

(2)

Given hasfactor x+2

, put=-2 and p(x)=0 and find first equation

Spoiler:

andwhen p(x) is divided by x+3, the remainder is 60.

, put=-3 and p(x)=60 and find second equation

Spoiler:

solve these two equation to find a and b

i got a= 1, b=-28

continue....