Question

Find the value of 64a^3+125b^3 if 4a+5b=-2 and ab=1/15.​

Answer 1

Answer:

64a³+125b³=0

Step-by-step explanation:

4a+5b=(-2)

Cubing on both the sides

(4a+5b)³=(-2)³

(4a)³+(5b)³+3(4a)(5b)[4a+5b]=(-8)

64a³+125b³+60ab(4a+5b)=(-8)

64a³+125b³+60(1/15)(-2)=(-8)

64a³+125b³+(-8)=(-8)

64a³+125b³-8=(-8)

64a³+125b³=(-8)+8

64a³+125b³=0