What is the equation of a parabola that is a vertical translation of y=x^2+3x of 1 and a horizontal translation of 5?

The form of a parabola reaching an extremum value of ${y}_{0}$ when $x = {x}_{0}$ is
$y - {y}_{0} = a {\left(x - {x}_{0}\right)}^{2} + b \left(x - {x}_{0}\right)$