Distribute 5 to all monomials inside the parenthesis
5(m + 4) = 5m + 20
5m + 20 = 2m + 20
Isolate the m, subtract 2m from both sides, and 20 from both sides
5m (-2m) + 20 (-20) = 2m (-2m) + 20 (-20)
5m - 2m = 20 - 20
Simplify
3m = 0
isolate the m, divide 3 from both sides
3m/3 = 0/3
m = 0/3
m = 0
hope this helps