55乘98加110
=55x98+55x2
=55x(98+2)
=55x100
=5500
550+55乘68+22乘55
=55x10+55x68+22x55
=55x(10+68+22)
=55x100
=5500
4000除以160
=4000÷40÷4
=100÷4
=25