化簡比：4:2=2:1 10:100=1:10 50:5=10:1 369:3=123:1 0.5:0.1=5:1 70:35=2:1 25:100=1:4 35:105=1:3 2000:10=200:1 3.5:70=1:20 0.1:0.2=1:2 300:300=1:1 55:110=1:2 4:400=1:100 66:6600=1:100 1.2:24=1:20 50:150=1:3 8000:2=4000:1 19:190=1:10 63:9=7:1求比值：4:2=2 10:100=10 50:5=10 369:3=123 0.5:0.1=5 70:35=2 25:100=1/4 35:105=1/3 2000:10=200 3.5:70=1/20 0.1:0.2=0.5 300:300=1 55:110=0.5 4:400=0.01 66:6600=0.01 1.2:24=0.05 50:150=1/3 8000:2=4000 19:190=0.1 63:9=7 解方程：3X=9X=9÷3X=30.1X=10X=10÷0.1X=10050X=50X=50÷50X=10.2X+0.2=0.40.2X=0.4-0.20.2X=0.2X=188X=8800X=8800÷88X=1000.6X=0.06X=0.06÷0.60.01800-100X=100100X=800-100100X=700X=700÷100X=745-45X=4545X=45-4545X=0X=0÷45X=080X+80=32080X=320-8080X=240X=240÷80X=325X-12.5=37.525X=37.5+12.525X=50X=50÷25X=2