100-7.32÷2.4x2.8
=100-7.32÷（1.2×2）×2.8
=100-7.32÷1.2÷2×2.8
=100-6.1×（2.8÷2）
=100-6.1×1.4
=100-（6+0.1）×1.4
=100-8.4-0.14
=91.6-0.14
=91.46
8.5+1.52÷0.5-2.6
=8.5+1.5×2÷（0.5×2）-2.6
=8.5+3-2.6
=8.5+0.4
=8.9