1.3.2×1.4+5.62
=3.2×(1+0.4)+5.62
=3.2×1+3.2×0.4+5.62
=10.1
2.10-1.8×1.2
=10-1.8×(1+0.2)
=10-1.8×1+1.8×0.2
=10