1) 36M^2 N^3 - 49 M^4 N = 6^2*M^2*N^3 - 7^2*M^4* N = M^2*N*(6^2 N^2 - 7^2M^4) =
= M^2N*(6N - 7M^2)(6N + 7M^20
...............................................
2) 50 + 20X + 2X^2
2X^2 + 20X + 50 = 0
D = 400 - 4*2*50 = 400 - 400 = 0
X = - 20 \ 4 = - 5
Выражение 50 + 20X + 2X^2 = (x +5)*(X+5)
(или (X + 5)^2 )