用简便方法计算下列各题.①(22+25)X4,②105X34一5X34,③103X32,④99X121,

Question

如题所述

Answer 1

(22+25)×4
=22×4+25×4
=88+100
=188
105×34-5×34
=(105-5)×34
=100×34
=3400
103×32
=(100+3)×32
=100×32+3×32
=3200+96
=3296
99×121
=(100-1)×121
=12100-121
=11979