Question

if p=-2,q=-1,r=3thenp3+q3+r3+3pqr

Answer 1

Just plug in the values. 

-2(3) + -1(3) + 3(3) + 3(-2)(-1)(3) = 
18

Answer 2

p3+q3+r3+3pqr
= (3x -2) + (-1×3) + (3x3) + 3x (-2) × (-1) × 3
= -6 -3 + 9 + 18
= 18