4×0.8×1.25×0.25
5.8×25%+0.25×4.2
72÷80%-100×72% 1.25×32×25%
13.7-3.6-4.3-2.1
0.59×101
2.5×12.5×40×0.8
()×24
24×+75÷5+
9×3.45+11.1×180%+54.3÷
70÷(1﹣86%) 25%×48×12.5×4 [13﹣(38.2﹣36)]÷7.2
17.1×42%-0.42×7.1
6.28×370%+6.28×6.3
0.25×3+25%×5 6.25×20×50%
一个数加上它的50%等于7.5,求这个数.解:设要求的这个数是X.列出方程:.
901-698≈ 391÷41≈ ( + )×12= 3.9×4×0.25=