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
Factorise the following expressions
m2 + m – 72
Using the identity (a + b)(a – b) = a2 – b2, find the following product
(1 + 3b)(3b – 1)
The pathway of a square paddy field has 5 m width and length of its side is 40 m. Find the total area of its pathway. (Note: Use suitable identity)
Factorise the following using the identity a2 – b2 = (a + b)(a – b).
3a2b3 – 27a4b
Factorise the following using the identity a2 – b2 = (a + b)(a – b).
28ay2 – 175ax2
Factorise the following using the identity a2 – b2 = (a + b)(a – b).
a4 – (a – b)4
Factorise the following using the identity a2 – b2 = (a + b)(a – b).
(a – b)2 – (b – c)2
Factorise the following using the identity a2 – b2 = (a + b)(a – b).
`x^2 - y^2/100`
Factorise the expression and divide them as directed:
(2x3 – 12x2 + 16x) ÷ (x – 2)(x – 4)
Verify the following:
(m + n)(m2 – mn + n2) = m3 + n3
