If a+b=3 and a^2+b^2=40.find the value of a^3+b^3
Answers
Answered by
21
a+b = 3
(a+b)^2 = 3^2
a^2+b^2+2ab = 9
but a^2+b^2 = 40
so,,,40 + 2ab = 9
2ab = 9-40
ab = -31/2
a^3+b^3 = (a+b) (a^2+b^2 - ab)
a^3+b^3 = 3×{40-(-31/2)}
a^3+b^3 = 3×(40+31/2)
a^3+b^3 = 3×111/2
a^3+b^3 = 333/2
(a+b)^2 = 3^2
a^2+b^2+2ab = 9
but a^2+b^2 = 40
so,,,40 + 2ab = 9
2ab = 9-40
ab = -31/2
a^3+b^3 = (a+b) (a^2+b^2 - ab)
a^3+b^3 = 3×{40-(-31/2)}
a^3+b^3 = 3×(40+31/2)
a^3+b^3 = 3×111/2
a^3+b^3 = 333/2
Answered by
6
bro its very easy u can find it by your own
buy the way see your answer
buy the way see your answer
Attachments:
Similar questions