Write each of the following quadratic functions in vertex form. Identify the vertex and axis of symmetry in each case.

a) $j(x) = x^2 - 12 x+ 42$
$j(x) =$
Vertex: $($ , $)$
Axis of symmetry: ? x = j(x) =

b) $k(x) = 2 x^2 + 12 x + 12$
$k(x) =$
Vertex: $($ , $)$
Axis of symmetry: ? x = k(x) =

c) $m(t) = 5 t^2 - 22$
$m(t) =$
Vertex: $($ , $)$
Axis of symmetry: ? t = m(t) =

d) $n(t) = t^2 - 8 t+9$
$n(t) =$
Vertex: $($ , $)$
Axis of symmetry: ? t = n(t) =

Hint: