if x +( 1/4x) =(3/2), find the value of 8 x3 + (1/8x3 ).
Answers
Answered by
5
x + 1/4x = 3/2
(x + 1/4x)³ = (3/2)³
x³ + 1/64x³ + 3(x)(1/4x)(x + 1/4x) = 27/8
x³ + 1/64x³ + 3/4(3/2) = 27/8
x³ + 1/64x³ + 9/8 = 27/8
x³ + 1/64x³ = 18/8
8x³ + 1/8x³ = 18. (multiplied by 8 both side)
(x + 1/4x)³ = (3/2)³
x³ + 1/64x³ + 3(x)(1/4x)(x + 1/4x) = 27/8
x³ + 1/64x³ + 3/4(3/2) = 27/8
x³ + 1/64x³ + 9/8 = 27/8
x³ + 1/64x³ = 18/8
8x³ + 1/8x³ = 18. (multiplied by 8 both side)
Similar questions