Упростить выражение
10c*10c+4d/25c^2+20cd+4d^2*15cd
(10c)*(10c+4d)/((25c^2+20cd+4d^2)*15cd)=
=(5с)*2*2*(5с+2d)/ ((5c+2d)^2)*(5c)*(3d)=
=4/( (5c+2d) *3d)