Advertisements
Advertisements
प्रश्न
If `5x + (1)/(5x) = 7`; find the value of `125x^3 + (1)/(125x^3)`.
बेरीज
Advertisements
उत्तर
`5x + (1)/(5x) = 7`
Using `("a" + 1/"a")^3`
= `"a"^3 + (1)/"a"^3 + 3("a" + 1/"a")`, we get :
`(5x + 1/(5"x"))^3`
= `(5x)^3 + (1/(5x))^3 + 3(5x + 1/(5x))`
⇒ 343 = `125x^2 + (1)/(125x^3) + 3(7)`
⇒ `125x^3 + (1)/(125x^3)`
= 343 - 21
= 322.
shaalaa.com
या प्रश्नात किंवा उत्तरात काही त्रुटी आहे का?
APPEARS IN
संबंधित प्रश्न
Expand.
`(x + 1/x)^3`
Expand.
`((5x)/y + y/(5x))^3`
If a + 2b + c = 0; then show that: a3 + 8b3 + c3 = 6abc.
Use property to evaluate : 93 - 53 - 43
Use property to evaluate : 383 + (-26)3 + (-12)3
If a ≠ 0 and `a - 1/a` = 4; find: `(a^2 + 1/a^2)`
If `3x - (1)/(3x) = 9`; find the value of `27x^3 - (1)/(27x^3)`.
Simplify:
(a + b)3 + (a - b)3
Expand: `((2m)/n + n/(2m))^3`.
Expand (52)3
