(朝阳区)求下列各式中的x. (1)x﹣20%x+7=17 (2):x=:3.
(3.75+4.1+2.35)×9.8 1.28+9.8+7.72+10.2
2.5×4.4 25×1.25×32
3.35×6.4×2+6.7×3.6 18.7-3.375-6.625
125×(8+0.8+0.08) 45÷〔78-(25+38)
1.3-3.79+9.7-6.21 8×0.4×12.5×2.5