Advertisements
Advertisements
प्रश्न
If a + b = 6 and ab = 20, find the value of a3 − b3
उत्तर
In the given problem, we have to find the value of `a^3 - b^3`
Given `a-b = ,ab = 20`
We shall use the identity
`a^3 -b^3 = (a-b)^3 3ab (a-b)`
`a^3 -b^3 = (a-b)^3 + 3ab(a-b)`
`a^3 - b^3 = (6)^3 3 xx 20(6)`
`a^3 - b^3 = 216 +360`
`a^3 -b^3 = 576`
Hence the value of `a^3 - b^3`is 576.
APPEARS IN
संबंधित प्रश्न
Use suitable identity to find the following product:
(x + 8) (x – 10)
Expand the following, using suitable identity:
`[1/4a-1/2b+1]^2`
What are the possible expressions for the dimensions of the cuboids whose volume is given below?
| Volume : 3x2 – 12x |
if `x^2 + 1/x^2 = 79` Find the value of `x + 1/x`
Simplify the following products:
`(x/2 - 2/5)(2/5 - x/2) - x^2 + 2x`
Simplify (2x + p - c)2 - (2x - p + c)2
Evaluate of the following:
1043 + 963
Simplify of the following:
Find the following product:
Evaluate:
483 − 303 − 183
If a1/3 + b1/3 + c1/3 = 0, then
Use the direct method to evaluate the following products :
(8 – b) (3 + b)
Evaluate: `(3"x"+1/2)(2"x"+1/3)`
If p + q = 8 and p - q = 4, find:
pq
If `"a"^2 - 7"a" + 1` = 0 and a = ≠ 0, find :
`"a" + (1)/"a"`
If `"r" - (1)/"r" = 4`; find : `"r"^4 + (1)/"r"^4`
Simplify:
(x + y - z)2 + (x - y + z)2
Using suitable identity, evaluate the following:
1033
Factorise the following:
4x2 + 20x + 25
Expand the following:
(–x + 2y – 3z)2
