Advertisements
Advertisements
प्रश्न
If 3x - `4/x` = 4; and x ≠ 0 find : 27x3 - `64/x^3`
Advertisements
उत्तर
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
संबंधित प्रश्न
Expand : ( x - 8 )( x - 10 )
Expand : `( 3a + 2/b )( 2a - 3/b )`
Expand : ( 5a - 3b + c )2
If x + 2y + 3z = 0 and x3 + 4y3 + 9z3 = 18xyz ; evaluate :
`[( x + 2y )^2]/(xy) + [(2y + 3z)^2]/(yz) + [(3z + x)^2]/(zx)`
If 2( x2 + 1 ) = 5x, find :
(i) `x - 1/x`
(ii) `x^3 - 1/x^3`
If 2( x2 + 1 ) = 5x, find :
(i) `x - 1/x`
(ii) `x^3 - 1/x^3`
If a2 + b2 = 34 and ab = 12; find : 3(a + b)2 + 5(a - b)2
The difference between two positive numbers is 4 and the difference between their cubes is 316.
Find : Their product
If 3a + 5b + 4c = 0, show that : 27a3 + 125b3 + 64c3 = 180 abc
If x = `1/( x - 5 ) "and x ≠ 5. Find" : x^2 - 1/x^2`
