4A= 4.( 1.2.3+2.3.4+4.5.6+5.6.7+...+2014.2015.2016
4A= 1.2.3.4 + 2.3.4.4 + 3.4.5.4 + .4.5.6.4 + ....+ 2014.2015.2016.4
4A= 1.2.3.4 + 2.3.4.(5 - 1)+ 3.4.5.( 6-2)+.....+ 2014.2015.2016.(2017-2013)
4A= 1.2.3.4+ 2.3.4.5-1.2.3.4.+ 3.4.5.6-2.3.4.5+ .....+ 2014.2015.2016.2017-2013.2014.2015.2016
4A = 2013.2014.2015.2016
A = 4117265071920
Tính nhanh:
1.2.3+2.3.4+3.4.5+4.5.6+5.6.7
- Tính giá trị biểu thức : C=1.2.3+2.3.4+3.4.5+4.5.6+5.6.7+6.7.8+7.8.9+8.9.10
1.2.3 + 2.3.4 + 3.4.5 + 4.5.6 + 5.6.7 + 6.7.8 + 7.8.9
1.2.3+2.3.4+3.4.5+4.5.6+5.6.7+6.7.8+7.8.9+8.9.10
B=1.3+3.5+5.7+...+97.98
C=1.2.3+2.3.4+3.4.5+4.5.6+5.6.7+7.8.9+8.9.10
D=1.2.3+2.3.4+...+99.100.101
Tính
a, 2.4+4.6+6.8+......+100.102
b, 8.10+10.12+12.14+.....+98.100
c, 1.2.3+2.3.4+4.5.6+5.6.7
A=1.2.3-2.3.4+3.4.5-4.5.6+5.6.7/2.4.6-4.6.8+6.8.10-810.12+10.12.14
Trả lời nhanh cho mình ạ
\(C=1.2.3+2.3.4+3.4.5+4.5.6+5.6.7+6.7.8+7.8.9+8.9.10=?\)
A =\(\frac{1.2.3-2.3.4+3.4.5-4.5.6+5.6.7-6.7.8}{2.4.6-4.6.8+6.8.10-8.10.12+10.12.14-12.14.16}\)
Rút gọn biểu thức
