Question

Решите систему уравнений:
x+y=7
5x-7y=11

Answer 1

x+y=7
5x-7y=11

х=7-у
5(7-у)-7у=11
35-5у-7у=11
-12у=11-35
-12у=-24
у=2

х+2=7
х=7-2
х=5

Answer 2

x=7-y 5(7-y)-7y=11 x=7-y 35-5y-7y=11 x=7-y -12y=-24 x=7-y y=2 x=5 y=2