find the value of 64a3+125b3 if 4a+5b=-1 and ab=1 help plz
Answers
Answered by
22
Answer:
Step-by-step explanation:
64a^3 + 125b^3 = (4a)^3 + (5b)^3
a^3 + b^3 = (a+b)( a^2 + b^2 -ab)
(a+b)^2 = a^2 + b^2 +2ab
a^2 + b^2 = (a+b)^2 - 2ab
so,
64a^3 + 125b^3 = (5)((a+b)^2 - 2ab - ab)
= 5((5)^2 - 3ab)
=5(25 - 3(-1))
= 5(25+3)
= 5(28)
= 140
Hope this helps you...
Answered by
3
Answer:
sorry I don't know the answer
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