5.5×4÷4.5÷0.25=5.5×4×4÷4.5=22×4÷4.5=88÷4.5=19又9分之5
5.5×4÷4.5÷0.25=11/2×4×2/9×4=22×2/9×4=44/9×4=176/9
原式=5.5×4+4.5×4=4×(5.5+4.5)=4×10=40
5.5x4÷4.5÷0.25=22x2/9 x4=176/9