计算:(1)1.23452+0.76552+2.469×0.7655=______;(2)19492-19502+195
来源:学生作业帮 编辑:作业帮 分类:数学作业 时间:2024/10/04 08:22:54
计算:
(1)1.23452+0.76552+2.469×0.7655=______;
(2)19492-19502+19512-19522+…+19972-19982+19992=______;
(1)1.23452+0.76552+2.469×0.7655=______;
(2)19492-19502+19512-19522+…+19972-19982+19992=______;
(1)1.23452+0.76552+2.469×0.7655=(1.2345+0.7655)2=22=4;
(2)19492-19502+19512-19522+…+19972-19982+19992=19492+(19512-19502)+…(19992-19982)
=19492+1×3901+3905×1+…+3997×1
=19492+
50(3901+3997)
2
=3897326,
故答案为4,3897326.
(2)19492-19502+19512-19522+…+19972-19982+19992=19492+(19512-19502)+…(19992-19982)
=19492+1×3901+3905×1+…+3997×1
=19492+
50(3901+3997)
2
=3897326,
故答案为4,3897326.
计算:(1)1.23452+0.76552+2.469×0.7655=______;(2)19492-19502+195
利用因式分解计算:(1)2022+202×196+982=______(2)652-352=______.
计算:(1)12.5×111-1.5×25=______.(2)49.2492492÷1.23123123=______
计算(-2)100+(-2)101=______.
计算:(x+5)(x-1)=______.
计算:(-2ab3)2=______.
计算(lg2)2+lg2•lg50+lg25=______
计算:(-4x-3y)2=______.
先找规律、再计算(1)140+150+160+170+180=______×______=______(2)230+24
设i是虚数单位,计算复数2i×(1+i)2=______.
计算:(-2x)(-3x2)2=______,(a+3)(a-2)=______.
计算:(1)3+5+7+9+…+73+75=______;(2)8888×1111+4444×7778=______.