Question

решите систему уравнений 3х+5у=12 и х-2у=-7

Answer 1

3х+5у=12
 х-2у=-7
3х+5у=12
х=-7+2у
3*(-7+2у)+5у=12
х=-7+2у
-21+6у+5у=12
х=-7+2у
11у=12+21
х=-7+2у
11у=33
х=-7+2у
у=33:11
х=-7+2у
у=3
х=-7+2*3
у=3
х=-1

Answer 2

Спасибо