题目内容
4.计算题4.83×0.59+0.41×1.59-0.324×5.9=
0.5×0.32×1.25×0.025×0.2=
567×234234234-234×567567567=
3x-4×(34÷2-x)=2. x=
5x+8(50-x)=2×215-5x. x=
分析 (1)运用乘法的分配律进行简算;
(2)把0.32分成0.4×0.8,再利用乘法的交换律和结合律进行简算;
(3)运用乘法的分配律进行简算;
(4)先化简方程,再根据等式的性质,方程两边同时加上68,再两边同时除以7求解;
(5)先化简方程,再根据等式的性质,方程两边同时加上68,再两边同时除以7求解.
解答 解:(1)4.83×0.59+0.41×1.59-0.324×5.9
=4.83×0.59-3.24×0.59+0.41×1.59
=(4.83-3.24)×0.59+0.41×1.59
=1.59×0.59+0.41×1.59
=1.59×(0.59+0.41)
=1.59×1
=1.59;
(2)0.5×0.32×1.25×0.025×0.2
=0.5×0.4×0.8×1.25×0.025×0.2
=0.5×0.2×0.8×1.25×0.025×0.4
=(0.5×0.2)×(0.8×1.25)×(0.025×0.4)
=0.1×1×0.01
=0.001;
(3)567×234234234-234×567567567
=567×234×1001001-234×567×1001001
=567×234×1001001×(1-1)
=567×234×1001001×0
=0;
(4)3x-4×(34÷2-x)=2
3x-4×(17-x)=2
3x-68+4x=2
7x-68=2
7x-68+68=2+68
7x=70
7x÷7=70÷7
x=10;
(5)5x+8(50-x)=2×215-5x
5x+400-8x=430-5x
400-3x=430-5x
400-3x+5x=430-5x+5x
400+2x=430
400+2x-400=430-400
2x=30
2x÷2=30÷2
x=15.
点评 本题考查了四则混合运算中的简算,要结合数据的特点,选择合适的简算方法;以及利用等式的性质解方程,注意等号对齐.