3/5x=453-3x=1x-0.9x=9.16x-7x=1693x+x=7.8x+120%=6.69.6÷x=80(1-25%)x=75040-x=0.880+20x=20019x+6=29180%x=120x+120%x=6612x+34x=118x-14x=1223x-5×14=1412+34x=5622-14x=1223x-14x=14X-5.7=2.15155X-2X=183X+0.7=53200=450+5X+XX-0.8X=6x+5.6=9.412x=300-4x7x+5.3=7.43x÷5=4.830÷x+25=85我建议楼主去买一本口算速算天天练,上面有很多
7χ-2×9=80
7+5χ=42
100-2X=50
13χ-7.5χ=18.7
(χ+12)×6=108
180÷X=12