Explain this to me please.
\(\frac{m-3}{4}=\frac{m+1}{3}\)
[m - 3] / 4 = [m + 1 ] / 3 cross-multiply
3 [ m - 3 ] = 4 [ m + 1] simplify
3m - 9 = 4m + 4 add 9 to both sides, subtract 4m from both sides
-1m = 13 divide both sides by -1
m = -13
