Answer :

luana
[tex] \left \{ {{7x+5y=15\ \ |*4} \atop {-6x-4y=-14\ \ |*5}} \right. \\\\ \left \{ {{28x+20y=60} \atop {-30x-20y=-70}} \right. \\+------\\ -2x=-10\ \ \ |Divide\ by\ -2\\ x=5\\\\ 5y=15-7x\\ 5y=15-7*5\\ 5y=15-35\\ 5y=-20\ \ \ |:5\\ y=-4\\\\\ Solution\ is\ B(5,-4).[/tex]