Question

如何解方程(x-2)/0.2-(x+1)/0.5=3 (0.04x+0.9)/0.5-(x-1)/2=(0.03+0.02x)/0.03

Answer 1

(x-2)/0.2-(x+1)/0.5=3
5(x-2)-2(x+1)=3
5x-10-2x-2=3
3x=15
x=5
(0.04x+0.9)/0.5-(x-1)/2=(0.03+0.02x)/0.03
(4x+90)/50-(x-1)/2=(3+2x)/3
3 (4x+90)-75(x-1)=50(3+2x)
12x+270-75x+75=150+100x
163x=195
x=195/163

Answer 2

(1)
(x-2)/0.2-(x+1)/0.5=3
0.5(x-2)-0.2(x+1)=3
0.3x-1.2=3
x=4.2/0.3=14
(2)
(0.04x+0.9)/0.5-(x-1)/2=(0.03+0.02x)/0.03
0.06*(0.04x+0.9)-0.015*(x-1)=0.03+0.02x
0.0024x+0.054-0.015x+0.015=0.03+0.02x
-0.0326x=-0.039
x=195/163