Answer
$ y=-5x+7$
Work Step by Step
Slopes are same for parallel lines. Slope is obtained by comparing $y=-5x+4$ with $y=mx+b$.
$m=-5$
Given point is $(1,2)$
$y-y_{1}=m(x-x_{1})$
$\implies y-2=-5(x-1)$
$\implies y-2=-5x+5$
$\implies y=-5x+5+2$
$\implies y=-5x+7$
