69.6÷2.4+17.92
=29+17.92
=46.92
15.8×10.1+0.62
=15.8x(10+0.1)+0.62
=158+1.58+0.62
=158+2.2
=160.2
6.8-20.16÷7.2
=6.8-2.8
=4