Advertisements
Advertisements
प्रश्न
If a + b = 10 and ab = 21, find the value of a3 + b3
Advertisements
उत्तर
In the given problem, we have to find the value of `a^3 + b^3`
Given `a+b = 10, ab = 21`
We shall use the identity `(a+b)^3 = a^3 +b^3 +3ab(a+b)`
Here putting, `a+b = 10,ab= 21`
`(10)^3 = a^3+ b^3 +3 (21)(10)`
` 1000 = a^3 +b^3 +630`
`1000 - 630 = a^3 +b^3`
`370 = a^3 + b^3`
Hence the value of `a^3 +b^3` is 370.
APPEARS IN
संबंधित प्रश्न
Use suitable identity to find the following product:
(x + 4) (x + 10)
Evaluate the following product without multiplying directly:
104 × 96
Factorise:
27x3 + y3 + z3 – 9xyz
Without actually calculating the cubes, find the value of the following:
(28)3 + (–15)3 + (–13)3
If 2x + 3y = 8 and xy = 2 find the value of `4x^2 + 9y^2`
Simplify the following products:
`(1/2a - 3b)(1/2a + 3b)(1/4a^2 + 9b^2)`
Simplify the following products:
`(m + n/7)^3 (m - n/7)`
Write in the expanded form:
`(m + 2n - 5p)^2`
Find the cube of the following binomials expression :
\[\frac{3}{x} - \frac{2}{x^2}\]
If \[x - \frac{1}{x} = 7\], find the value of \[x^3 - \frac{1}{x^3}\].
If 2x+3y = 13 and xy = 6, find the value of 8x3 + 27y3
If \[x + \frac{1}{x} = 3\] then find the value of \[x^6 + \frac{1}{x^6}\].
If \[x - \frac{1}{x} = \frac{1}{2}\],then write the value of \[4 x^2 + \frac{4}{x^2}\]
If \[\frac{a}{b} + \frac{b}{a} = 1\] then a3 + b3 =
Find the square of : 3a - 4b
Use identities to evaluate : (97)2
If `x + (1)/x = 3`; find `x^4 + (1)/x^4`
If p + q = 8 and p - q = 4, find:
pq
If `"a"^2 - 7"a" + 1` = 0 and a = ≠ 0, find :
`"a" + (1)/"a"`
Expand the following:
(4a – b + 2c)2
