equation for slope intercept form is
y-y1=m(x-x1)
where m is slope and (x1,y1) are coordinate points
here (-3,1) are points we take
y-1=m(x+3)
to find the value of m we know this line is parallel to line y=2x-4
here m=2
so put this m into first equation
y-1=2(x+3) (parallel lines have same slope)
this is the required equation y-1=2(x+3)
