Advertisements
Advertisements
प्रश्न
Find the value of 4x2 + y2 + 25z2 + 4xy − 10yz − 20zx when x = 4, y = 3 and z = 2.
Advertisements
उत्तर
We have,
`4x^2 + y^2 + 25z^2 + 4xy - 10yz - 20zx`
`=> (2x)^2 + (y)^2 + (-5z)^2 + 2(2x)(y) + 2(y)(-5z) + 2(-5z)(2x)`
`=:> (2x + y - 5z)^2`
`=> [2[4] + 3 - 5(2)]^2` [∵ x = 4, y = 3 and z = 2]
`= [8 + 3 - 10]^2`
`=[1]^2`
= 1
`∴ 4x^2 + y^2 + 25z^2 + 4xy - 10yz - 20zx = 1`
APPEARS IN
संबंधित प्रश्न
Write in the expanded form:
(2a - 3b - c)2
Write in the expanded form: `(x/y + y/z + z/x)^2`
Evaluate of the following:
1113 − 893
If x = 3 and y = − 1, find the values of the following using in identify:
\[\left( \frac{5}{x} + 5x \right)\] \[\left( \frac{25}{x^2} - 25 + 25 x^2 \right)\]
If a + b = 6 and ab = 20, find the value of a3 − b3
If x = −2 and y = 1, by using an identity find the value of the following
If \[\frac{a}{b} + \frac{b}{a} = - 1\] then a3 − b3 =
If a1/3 + b1/3 + c1/3 = 0, then
Use identities to evaluate : (502)2
If a - b = 0.9 and ab = 0.36; find:
(i) a + b
(ii) a2 - b2.
If 3x + 4y = 16 and xy = 4, find the value of 9x2 + 16y2.
If `"a" + 1/"a" = 6;`find `"a"^2 - 1/"a"^2`
If `"a"^2 - 7"a" + 1` = 0 and a = ≠ 0, find :
`"a" + (1)/"a"`
If `"p" + (1)/"p" = 6`; find : `"p"^2 + (1)/"p"^2`
If `"a" + (1)/"a" = 2`, then show that `"a"^2 + (1)/"a"^2 = "a"^3 + (1)/"a"^3 = "a"^4 + (1)/"a"^4`
Simplify:
(3x + 5y + 2z)(3x - 5y + 2z)
The value of 2492 – 2482 is ______.
If `x/y + y/x = -1 (x, y ≠ 0)`, the value of x3 – y3 is ______.
Find the value of x3 – 8y3 – 36xy – 216, when x = 2y + 6
