Question

解二元一次方程组,急用!0.8x-1.7y=-75x-3y=24x+y=45x-1=1.8-x-6yx/5-y/2=-4

Answer 1

0.8x-1.7y=-7(1)

5x-3y=2(2)

(1)*50-(2)*8

40x-85y-40x+24y=-350-16

-61y=-366

y=6

x=4

4x+y=4.5 (1)

x-1=1.8-x-6y

2x+6y=2.8

x+3y=1.4 (2)

(1)×3-(2)

12x+3y-x-3y=13.5-1.4

11x=12.1

x=1.1

y=4.5-4x=0.1

下面有点烦 只怪你分太少