40%+40%(x-30)+120=x 怎么解
问题描述：
40%+40%(x-30)+120=x 怎么解
答
40%+40%x-12+120=x x-40%x=40%+108 60 %x=108.4 x=542/3
答
40%+40%(x-30)+120=x 0.4+0.4x-12+120=x 0.6x=108.4 x=1084/6=542/3
答
0.4+0.4X-12+120=x 120.4-12=0.6x 108.4=0.6X x=
答
40％+40％X+12+120-X=0 132.4-0.6X=0 X=662\3