Question

7x-2y=5x+6y=7

解两道二元一次方程组（写过程）
(1)7x-3y=5,-5x+6y=-6
(2)x/4+y/3=7,x/3+y/2=8

Answer 1

(1)7x-3y=5 (1)
-5x+6y=-6 (2)
(1)*2+(2)
14x-6y-5x+6y=10-6
9x=4
x=4/9
y=(7x-5)/3=-17/27
(2)x/4+y/3=7 (1)
x/3+y/2=8 (2)
(1)*1/2-(2)*1/3
x/8+y/6-x/9-y/6=7/2-8/3
x/72=5/6
x=60
y=(8-x/3)*2=-24