Question

The sum of (x+3)observations is (x^4-81).find the mean of observations

Answer 1

Hi Friend !!!

Here is ur answer !!!

The mean = x^4-81 / x+3

= (x²)²-9²/x+3

= (x²+9)(x²-9)/x+3

= (x²+9)(x²-3²)/x+3

= (x²+9)(x+3)(x-3)/x+3

= x²+9(x-3)


Hope it helps u : )

Answer 2

$mean = \frac{sum \: of \: the \: observations}{total \: number \: of \: observations } \\ = \frac{x {}^{4} - 81 }{x + 3} \\ = \frac{(x { {}^{2} ) { }^{2} - (9) {}^{2} }^{} }{x + 3 } \\ = \frac{(x {}^{2} + 9)(x { }^{2} - 9) }{x + 3} \\ = \frac{(x {}^{2} + 9)(x) {}^{2} - (3) {}^{2} }{x + 3} \\ = \frac{(x {}^{2} + 9)(x - 3)(x + 3) }{x + 3} \\ = (x {}^{2} + 9)(x - 3) \\ = x {}^{3} - 3x {}^{2} + 9x - 27 \: \: \\ so \: mean \: is \: x {}^{3} - 3x {}^{2} + 9x - 27$
Hope this will help you