7 The functions \(\mathrm { f } , \mathrm { g }\) and h are defined for all real values of \(x\) by
$$\mathrm { f } ( x ) = | x | , \quad \mathrm { g } ( x ) = 3 x + 5 \quad \text { and } \quad \mathrm { h } ( x ) = \mathrm { gg } ( x ) .$$
- Solve the equation \(\mathrm { g } ( x + 2 ) = \mathrm { f } ( - 12 )\).
- Find \(\mathrm { h } ^ { - 1 } ( x )\).
- Determine the values of \(x\) for which
$$x + \mathrm { f } ( x ) = 0 .$$