x÷3=8.4÷4.2x÷3=2x=2×3x=6
4.2x÷3=8.44.2x=8.4×34.2x=25.2x=6
4.2x÷3=8.4解:4.2x=8.4×34.2x=25.2x=25.2÷4.2x=6