Question

If A+B = 5 and AB=3 then find A³+B³=

Answer 1

Answer:

80

Step-by-step explanation:

A3+ B3 = (A+B)3 -3AB(A+B)

=(5)3 -3*3*5=125-45=80

Answer 2

Answer:

A ^3+B^3=( A+B )(A^2-AB+B^2)

Now find value of A^2+b^ 2 by using (A+B)^2

A^2+B^2 as 16 then substitute these values

=(5)(16-3)

=5*13

=65

A^3+B^3=65