Question

Solve the system using elimination.

7x + 5y = 15
–6x – 4y = –14  

A.(–6, 7)
B.(5, -4)
C.(7, –7)
D.(–4, 5)

Answer 1

`\left \{ {7x+5y=15\ \ \atop *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).`