Question

If a-b-8 and ab = -12, then a 3-b3 is equalto
(a) -244 (b)-240(C) -224 (dl] -260​

Answer 1

Answer:

As we know,

⇒ (a3 – b3) = (a – b) (a2 + b2 + ab)

3√3 x3 – 2√2 y3 = (x √3 – y √2) (Ax2 + By2 + Cxy)

⇒ (√3 x)3 – (√2 y)3 = (√3x – √2y) (Ax2 + By2 + Cxy)

⇒ (√3 x – √2 y) (3x2 + 2y2 + √6 xy) = (√3x – √2y) (Ax2 + By2 + Cxy)

⇒ 3x2 + 2y2 + √6xy = Ax2 + By2 + Cxy

On comparing

⇒ A = 3, B = 2 and C = √6

⇒ (A × 2) ÷ C

⇒ (3 × 2) ÷ (√6) = 6 ÷ (√6)

⇒ √6