Question

If f(x)=8-1x and g(x)=5x+4, what is the value of (fg)(-2)

Answer 1

The value of (fg)(-2) is 14

Explanation:

We are given
`f(x)=8-1x` and
`g(x)=5x+4` and we need to find (fg)(-2)

First we will replace the 'x' in f(x) with g(x) to find (fg)(x) i.e

`f(x) = 8 -1x\\(fg)(x) = 8 - 1(5x+4)\\(fg)(x) = 8 - 5x - 4\\(fg)(x) = - 5x+4`

Now we will put the value of x = -2 to find (fg)(-2) i.e

`(fg)(x) = - 5x+4\\(fg)(-2) = - 5(-2)+4\\(fg)(-2) = 10+4\\(fg)(-2) = 14`

So, the value of (fg)(-2) is 14