Question

if 3a+b=10 and ab=5 find 27a^3+b^3

Answer 1

Answer:

27a³ + b³ = 970

Step-by-step explanation:

we have

3a+b=10

cubing on both sides , we get

(3a+b)³ = 10³

27a³ + b³ + 6ab = 1000

given. ab = 5

substituting this value in above equation,

27a³ + b³ + 6×5 = 1000

27a³ + b³ = 1000-30

27a³ + b³ = 970