Question

Решить систему тремя способами:
1)Постановки;
2)Сложения;
3)Графический.
{{x+2y=18}}
{{-x+3y=2}}

Answer 1

$1); ; left { {{x+2y=18} atop {-x+3y=2}} right. ; left { {{3y-2+2y=18} atop {x=3y-2}} right. ; left { {{5y=20} atop {x=3y-2}} right. ; left { {{y=4} atop {x=3cdot 4-2}} right. ; left { {{y=4} atop {x=10}} right. \\2); ; left { {{x+2y=18} atop {-x+3y=2}} right. oplus left { {{5y=20} atop {-x+3y=2}} right. ; left { {{y=4} atop {-x+12=2}} right. ; left { {{y=4} atop {-x=-10}} right. ; left { {{y=4} atop {x=10}} right. \\3)$