Question

решите систему уравнений .

Answer 1

2x+3y=1
3x-y=7

2x+3y=1
y= -3x+7

2x+3y=1
y= -7+3x

2x+3(3x-7)=1
y= -7+3x

2x+9x-21=1
y= -7+3x

x=22/11=2
y=-7+(3*2)=-1

x=2
y= -1

Answer 2

$\left \{ {{2x+3y=1} \atop {3x-y=7}/*3} \right. \\ \\ \left \{ {{2x+3y=1} \atop {9x-3y=21}} \right. \\ 11x=22 \\ x=2 \\ 4+3y=1\\3y=-3\\y=-1 \\ \left \{ {{x=2} \atop {y=-1}} \right.$