(25-2.5)x4.1和12.5x0.7+12.5怎么简算还有(2.82x7+2.82)x1.25(6-5.96)x2.5+0.83都是怎么简算的
问题描述:
(25-2.5)x4.1和12.5x0.7+12.5怎么简算
还有
(2.82x7+2.82)x1.25
(6-5.96)x2.5+0.83
都是怎么简算的
答
(1)将2.82提出:原式=2.82x(7+1)x1.25
其中 8x1.25=10
原式=2.82x10=28.2
(2)第二题应该不用简化了
原式=0.04x2.5+0.83
=0.1+0.83
=0.93
答
(25-2.5)x4.1
=(25-2.5)x(4+0.1)
=(25-2.5)x4+(25-2.5)x0.1
=100-10+2.5-0.25
=90+2.25
=92.25
{(25-2.5)x4.1中,将4.1拆为(4+0.1),再把它们各项乘出来(即用4分别乘25和2.5,再相减,然后加上0.1分别乘25和2.5后的和}
12.5x0.7+12.5
=12.5x0.7+1.25-1.25+12.5
=12.5x(0.7+0.1)-1.25+12.5
=10-1.25+12.5
=21.25
(2.82x7+2.82)x1.25
=2.82x(7+1)x1.25
=2.82x(8x1.25)
=2.82x10
=28.2
(6-5.96)x2.5+0.83
=0.04x2.5+0.83
=0.1+0.83
=0.93