Question

2. If a+b=12 and ab=27, find the value of a3+b3.

Answer 1

Answer:

756

Step-by-step explanation:

a^3 + b^3 = (a+b) (a^2 -ab +b^2 )

as.. (a+b)^2 -2ab = a^2 +b^2

a^3 + b^3 = (a+b) {(a+b)^2 -3ab}

by this we can write that:

a^3+b^3 = 12 {(12)^2 -3*27}

---> 12 {144-81}

a^3+b^3 = 12*63 = 756