Advertisements
Advertisements
Question
If 3x - `4/x` = 4; and x ≠ 0 find : 27x3 - `64/x^3`
Advertisements
Solution
3x - `4/x` = 4;
We need to find 27x3 - `64/x^3`
Let us now consider the expansion of `( 3x - 4/x )^3` :
`( 3x - 4/x )^3 = 27x^3 - 64/x^3 - 3 xx 3x xx 4/x( 3x - 4/x )`
⇒ `(4)^3 = 27x^3 - 64/x^3 - 144 ["Given :" 3x - 4/x = 4]`
⇒ 64 + 144 = 27x3 - `64/x^3`
⇒ 27x3 - `64/x^3` = 208
APPEARS IN
RELATED QUESTIONS
Expand : ( x + 8 )( x - 10 )
Expand : ( x - 8 )( x - 10 )
Expand : `( x - 1/x + 5)^2`
If x + 2y + 3z = 0 and x3 + 4y3 + 9z3 = 18xyz ; evaluate :
`[( x + 2y )^2]/(xy) + [(2y + 3z)^2]/(yz) + [(3z + x)^2]/(zx)`
In the expansion of (2x2 - 8) (x - 4)2; find the value of coefficient of x2
If a2 + b2 = 34 and ab = 12; find : 7(a - b)2 - 2(a + b)2
If `(x^2 + 1)/x = 3 1/3` and x > 1; find If `x^3 - 1/x^3`
Find the value of 'a': 4x2 + ax + 9 = (2x + 3)2
Find the value of 'a': 4x2 + ax + 9 = (2x - 3)2
The sum of two numbers is 7 and the sum of their cubes is 133, find the sum of their square.
