Question

A function is defined as `f(x)=x^2+3` What is the simplified expression for `f(a+2) - f(a-5)`?

Answer 1

The expression is `=(14a-21)`

Explanation:

If `f(x)=x^2+3`

then ,
`f(a+2)=(a+2)^2+3`
`=a^2+4a+4+3=a^2+4a+7`

`f(a-5)=(a-5)^2+3`
`=a^2-10a+25+3=a^2-10a+28`

`f(a+2)-f(a-5)=(a^2+4a+7)-(a^2-10a+28)`
`=a^2+4a+7-a^2+10a-28`

`=14a-21`