（6.74+6.74除6.74―6.74）x6.74=1x6.74=6.74
〔1.8―1.8x（1.8―1.8）〕除0.36=1.8/0.36=5
（9x+59―5x）除3=29
9x+59―5x=81
4x=81-59=22
x=5.5