Question

Решите систему уравнений
4х+у=10
х+3у=-3

Answer 1

y=10-4x                              4умножить3+y=10
x+3(10-4x)=-3                    12+y=10
x+30-12x=-3                       y=10-12
x-12x=-3-30                        y=-2
-11x=-33                             (3;-2) 
x=-33:(-11)
x=3