Question

If a-b=5,ab=14 find the value of a cube - b cube

Answer 1

Step-by-step explanation:

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

(5)^2=a^2+b^2-2×14

25=a^2+b^2-28

25+28=a^2+b^2

53=a^2+b^2

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

a^3-b^3=5(53+28)

=5(81)

=405