Question

2x+3y=7метод сложения
7x-3y=6
___________________________
X+3y=13
2x+y=6

Answer 1

1.

$left { {{2x+3y=7} atop {7x-3y=6}} right. \\ left { {{9x=13} atop {2x+3y=7}} right. \ \ left { {{x=frac{13}{9}} atop {2*frac{13}{9}+3y=7}} right. \ \ left { {{x=frac{13}{9}} atop {y=frac{37}{27}}} right.$

2.

$left { {{x+3y=13} atop {2x+y=6 }} right. \ \ left { {{x+3y=13} atop {-6x-3y=-18 }} right.\ \ left { {{-5x=-5} atop {x+3y=13}} right. \ \ left { {x=1} atop {1+3y=13}} right. \ \ left { {{x=1} atop {y=4}} right.$