Question

Let `u(x)=2x-1` and `w(x)=x^2`, how do you find u(w(-4)) and w(u(-4))?

Answer 1

u(w(-4))=31 w(u(-4))=81

Explanation:

w(u(-4))

`u(x)=2x−1`
`u(-4)=2(-4)−1` (plug in -4)
`u(-4)=-8−1` (multiply)
`u(-4)=-9` (add)
`w(x)=x^2`
`w(u(-4))=(-9)^2` (plug u(-4)=-9 into w(x))
`w(u(-4))=81` (square)

u(w(-4))

`w(x)=x^2`
`w(-4)=(-4)^2` (plug in -4)
`w(-4)=16` (square)
`u(x)=2x−1`
`u(w(-4))=2(16)−1` (plug w(-4)=16 into u(x))
`u(w(-4))=32−1` (multiply)
`u(w(-4))=31` (add)

hope this helps