6.09乘3.6+0.36乘39.1 7.2除4.5 都要简便运算!

1) 6.09×3.6＋0.36×39.1
原式=6.09×3.6＋0.36×10×3.91
=6.09×3.6＋3.6×3.91
=3.6×(6.09＋3.91)
=3.6×10
=36
2) 7.2÷4.5
原式=7.2÷(9÷2)
=7.2÷9×2
=0.8×2
=1.6