Question

Помогите решить.
Не понимаю.

Answer 1

$1); ; left { {{y=x} atop {y=2-x}} right. ; ; to ; ; ; y=y; ; ; to ; ; ; x=2-x; ,; ; 2x=2; ,; x=1\\ y=x=1\\Otvet:; ; (1,1); .\\2); ; left { {{y=2x} atop {y=6-x}} right. ; ; left { {{y=2x} atop {2x=6-x}} right. ; left { {{y=2x} atop {3x=6}} right. ; left { {{y=2cdot 2} atop {x=2}} right. ; left { {{y=4} atop {x=2}} right. \\Otvet:; ; (2,4); .$

$3); ; left { {{x+2y=6} atop {x-y=4}} right. ; left { {{x=6-2y} atop {x=4+y}} right. ; left { {{6-2y=4+y} atop {x=4+y}} right. ; left { {{2=3y} atop {x=4+y}} right. ; left { {{y=frac{2}{3}} atop {x=4+frac{2}{3}}} right. \\left { {{y=frac{2}{3}} atop {x=4frac{2}{3}}} right. \\Otvet:; ; (4frac{2}{3},frac{2}{3}); .$

$4); ; left { {{2x-y=-1} atop {x+y=-2}} right. ; left { {{y=2x+1} atop {y=-x-2}} right. ; left { {{-x-2=2x+1} atop {y=-x-2}} right. ; left { {{3x=-3} atop {y=-x-2}} right. ; left { {{x=-1} atop {y=1-2}} right. \\ left { {{x=-1} atop {y=-1}} right. \\Otvet:; ; (-1,-1); .$