Question

4x - 7y = 3
x - 7y = 15

Answer 1

`\left \{ {{4x-7y=3} \atop {x-7y=15}} \right. \\\\ \left \{ {{4x-7y=3} \atop {x=15+7y}} \right. \\\\ substitution\ method\\\\ 4*(15+7y)-7y=3\\\\ 60+28y-7y=3\\\\ 60+21y=3\ \ \ \ | subtract\ \\\\ 21y=-57\\\\ y=-(57)/(21)=-(19)/(7)\\\\ x=15+7*(-(19)/(7))=15-19=-4\\\\\ Solution :\ \left \{ {{y=-(19)/(7)} \atop {x=-4}} \right.`