2.5+3.91÷(20_18.3) (4.6+8.4÷21)×1.5 0.13×3.67+
2.5+3.91÷(20_18.3)
(4.6+8.4÷21)×1.5
0.13×3.67+0.13×1.33
3.6×12.5÷0.36×0.8