Question

If (a2 + b2) = 100 and a = -8, then determine the value of (a + b)3 for b < 0.

Answer 1

a²+b² = 100

(-8)² +b² =100

64+b² =100

b² =100-64

b² = 36

b. =6

(a+b)³ = a³ +b³+3a²b+3ab²

= (-8)³ +(6)³ +3(-8)²(6)+3(-8)(6)²

= -512+216+1152-864

= -512-864+1152+216

= -1376+1368

= -18

Hope the answer help you