Advertisements
Advertisements
प्रश्न
The sum of (x + 5) observations is x4 – 625. Find the mean of the observations.
Advertisements
उत्तर
We have, the sum of (x + 5) observations = x4 – 625
We know that, the mean of the n observations x1, x2, ... xn is given by `(x_1 + x_2 + ... x_n)/n`.
∴ The mean of (x + 5) observations
= `("Sum of" (x + 5) "observations")/(x + 5)`
= `(x^4 - 625)/(x + 5)`
= `((x^2)^2 - (25)^2)/(x + 5)`
= `((x^2 + 25)(x^2 - 25))/(x + 5)` ...[∵ a2 – b2 = (a + b)(a – b)]
= `((x^2 + 25)[(x)^2 - (5)^2])/(x + 5)`
= `((x^2 + 25)(x + 5)(x - 5))/((x + 5))`
= (x2 + 25)(x – 5)
APPEARS IN
संबंधित प्रश्न
Expand: (3x + 4y)(3x - 4y)
Factorise the following algebraic expression by using the identity a2 – b2 = (a + b)(a – b)
z2 – 16
a2 – b2 = (a + b) ______.
672 – 372 = (67 – 37) × ______ = ______.
Factorise the following using the identity a2 – b2 = (a + b)(a – b).
x2 – 9
Factorise the following using the identity a2 – b2 = (a + b)(a – b).
1331x3y – 11y3x
Factorise the following using the identity a2 – b2 = (a + b)(a – b).
`1/36a^2b^2 - 16/49b^2c^2`
Factorise the following using the identity a2 – b2 = (a + b)(a – b).
16x4 – 81
Factorise the following using the identity a2 – b2 = (a + b)(a – b).
16x4 – 625y4
Verify the following:
(m + n)(m2 – mn + n2) = m3 + n3
