Question

решите систему 6m+5n=15 3m-35n=120

Answer 1

6m  + 5n = 15  
3m - 35n = 120   /*(-2)

6m + 5n = 15
- 6m + 70n = - 240
------------------------------ сложим

5n + 70n = 15 - 240
75n = - 225
n = - 3

m = (120 + 35n)/3 = (120 - 105)/3 = 5