Question

解这个方程组 x-1/5=y+3/2,x-1/2=1-y/2

要过程 (x-1)/5=(y+3)/2,x-1/2=(1-y)/2

Answer 1

补充：
（x-1）/5=（y+3）/2,2(x-1)=5(y+3),2x-5y=17.........(1)
x-1/2=（1-y）/2,2x-1=1-y,2x+y=2..........(2)
(2)-(1):
6y=-15
y=-2.5
x=(2-y)/2
=2.25

Answer 2

(x-1)/5=(y+3)/2,x-1/2=(1-y)/2

2x-2=5y+15,2x-1=1-y

2x=5y+17,2x=2-y

于是5y+17=2-y,6y=-15,y=-5/2

x=9/4,y=-5/2

Answer 3

x-1/5=y+3/2 ①, x-1/2=1-y/2 ②
①-②得 3/10=3y/2-1/3，解得 y=19/45
代入①式，得 x=58/45

Answer 4

x-y=1.7 (1)
x+y/2=1.5 (2)
(2)*2
2x+y=3 (3)
(1)+(3)
3x=4.7
x=47/30 带入(1) y=-2/15