Question

If a-b=6 and ab=20 find the value of a cube minus b cube

Answer 1

Answer:

576

Step-by-step explanation:

(a-b)^3 = a^3 -b^3 -3ab(a-b)   [identity]

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

a^3-b^3 =(6)^3 + 3(20)(6)

a^3-b^3 = 216 +  360

a^3-b^3 = 576

Answer 2

Answer:

576

Step-by-step explanation:

a-b=6

ab=20

a^3-b^3=?

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

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

=6^3+3×20×6

=216+360

=576

therefore:a^3-b^3=576