x:8=34:15 解:15x=8×34 15x×5=6×5 x=30 1 .6:x=0.125:0.5 解:0.125x=0.5×1.6 0.125x×8=0.8×8 x=6.4 x:1.2=3:4 解:4x=1.2×3 4x÷4=3.6÷4 x=0.9 32:15=34:x 解:32x=15×34 32x=320 32x÷32=320÷32 x=110 16:x=0.75:158 解:0.75x=16×158 34x=30 x=30×43 x=40 x2.4=5:3 解:3x=5×2.4 3x=12 3x÷3=12÷3 x=4 0.8:4=x:8 解:4x=0.8×8 4x÷4=6.4÷4 x=1.6 16:x=2.4:3 解:2.4x=16×3 2.4x÷2.4=48÷2.4 x=20 x:18.5=5:4 解:4x=18.5×5 4x÷4=92.5÷4 x=23.125
