3х+5у=12
х-2у=-7
х=2у-7
6у-21+5у=12
11у=33
у=3
х=6-7
х=-1
ответ (-1;3)
x=-7+2*y => 1) 3*(-7+2*y)+5*y=12 =>=> -21+6*y+5*y=12 11*y=33 y=3 x=-7+2*3=-1
3х+5у=12
х-2у=-7
х=2у-7
6у-21+5у=12
11у=33
у=3
х=6-7
у=3
х=-1
ответ (-1;3)
x=-7+2*y => 1) 3*(-7+2*y)+5*y=12 =>
=> -21+6*y+5*y=12
11*y=33
y=3
x=-7+2*3=-1