Question

If n-y=4y-n/m find n when y=3 and m=7

Answer 1

Move all terms to the left side, and set equal to zero. Then set each factor equal to zero.
n = 5my/m+1

Answer 2

n-y=4y-n/m
Forst we take care of the formula!
I did it this way
4y-n/m=n-y
4y-n-n=-ym
4y-2n=-ym
-2n=-ym/4y
Now we just replace y with 3 and m with 7
-2n=-3*7/4*3
-2n=-21/12
n=-22/12/2
n=-22/6
I think this is it