Question

Выражение: (5+m)^2+(m-2)(m+2)-2m(m+5)

Answer 1

$(5+m)^2+(m-2)(m+2)-2m(m+5)= \\ = m^2+10m+25+m^2-4-2m^2-10m = \\ = 3*7=21$

Answer 2

$(5+m)^2+(m-2)(m+2)-2m(m+5)= \\ 25+10m+m^2+m^2-4-2m^2-10m=21$