1.3x+2.7x=0.28
10-4x=8
5×3.2+2x=24
40-3.69÷18
3.14×42-3.14×32
62×0.98
6.3×103-0.63×30
1.8÷0.31.8
3.75753.7575…
7.3×0.27.3
2.5×42.5÷4