7.186×1.45+1.69×7.186+3.14×2.186
=7.186x(1.45+1.69)+3.14x2.186
=7.186x3.14+3.14x2.186
=3.14x(7.186+2.186)
=3.14x9.372
=29.42808
166又1/20÷41
=(164+41/20)÷41
=164÷41+41/20÷41
=4+1/20
=4.05