Question

if a+b = 3 and ab=2 then find a³+b³​

Answer 1

Answer:

cubing both the sides,

(a+b)^3 =3^3

a^3+b^3+3ab(a+b) =27

a^3+b^3+3×2(3) =27

a^3+b^3+18=27

a^3+b^3=9

Answer 2

Answer:

Step-by-step explanation:

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

(a-b)(a^2+2+b^2)

a(a^2+2+b^2)-b(a^2+2+b^2)

a^3+2a+2ab-2ab+2b+b^3

(a^3+2a)+(2b+b^3)

a(a^2+2)+b(2+b^2)

a+b(a^2+2+2+b^2)

3(a^2+4+b^2)

3a^2+12+3b^2