解方程. 19-12%x=7 2x+30%x=9.2 (1-25%)x=36 75%x+25=40 50%x=13/40 3/4x-50%x=17.5.

问题描述:

解方程.
19-12%x=7    
2x+30%x=9.2     (1-25%)x=36
75%x+25=40     50%x=
13
40
    
3
4
x-50%x=17.5.

(1)19-12%x=7        19-0.12x=7  19-0.12x+0.12x=7+0.12x         7+0.12x=19     &nbsp...