Answer :
X= y/m - b/m, because you multiple the whole equation by 1/m, getting y/m=x+b/m, and you subtract b/m from both sides, getting X=y/m-b/m
[tex]y=mx+b\\y-b=mx+b-b\\y-b=mx\\\frac{y-b}m=\frac{mx}m\\\\\boxed{\frac{y-b}m=x}[/tex]