Question

if a+b=8 and a^2+b^2=4 find a^3+b^3

Answer 1

Answer:

320

Step-by-step explanation:

first find ab

formula ......

a²+b² = (a+b)²-2ab

4 = (8)²- 2ab

4 = 64-2ab

2ab = 64÷4

ab = 8

then in last we find a³+b³

formula for a³+b³

# a³+b³ = (a+b)³-3ab(a+b)

a³+b³ = (8)³-3(8)×8

= 512-192

a³+b³ = 320