Question

Write the coefficient of x in the expansion of (x+5)^3?

Answer 1

75

Explanation:

`(x+5)^3=(x+5)(x+5)(x+5)`

`(x^2+5x+5x+25)(x+5)`

`(x^2+10x+25)(x+5)`

`x^3+10x^2+25x+5x^2+50x+125`

`x^3+15x^2+75x+125`