Question

13.If (2x - 2/x) =3 then 8x³ - 8/x³ is equal to​

Answer 1

ANSWER :–

63

SOLUTION :–

GIVEN :–

An equation (2x - 2/x) = 3.

TO FIND :–

8x³ - 8/x³

SOLUTION :–

• We know that –

☞ (a - b)³ = a³ - b³ - 3ab(a - b)

• Now put the values –

➪ (2x - 2/x)³ = 8x³ - 8/x³ - 3(2x)(2/x)(2x - 2/x)

➪ (3)³ = 8x³ - (8/x³) - 3(4)(3)

➪ 27 = 8x³ - (8/x³) - 36

➪ 8x³ - (8/x³) = 27 + 36

➪ 8x³ - (8/x³) = 63

EXTRA FORMULA :–

➪ (a + b)³ = a³ + b³ + 3ab(a + b)