![](https://rs.olm.vn/images/avt/0.png?1311)
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
![](https://rs.olm.vn/images/avt/0.png?1311)
![](https://rs.olm.vn/images/avt/0.png?1311)
A = 2 + ( 2+ 1).4 + ( 4 + 1)6 + … + (98 + 1).100
= 2 + 2.4 + 4 + 4.6 + 6 + … + 98.100 + 100
= (2.4 + 4.6 + … + 98.100 ) + (2 + 4 + 6 + … + 100)
= 98.100.102 : 6 + 102.50:2
= 166600 + 2550
= 169150
![](https://rs.olm.vn/images/avt/0.png?1311)
B x 3 = 1x2x3 + 2x3x3 + 3x4x3 + 4x5x3 + ... + 99x100x3
= 1x2x3 + 2x3x(4-1) + 3x4x(5-2) + 4x5x(6-3) + ... + 99x100x(101-98)
= 1x2x3 + 2x3x4 - 1x2x3 + 3x4x5 - 2x3x4 + 4x5x6 - 3x4x5 + ... + 99x100x101 - 98x99x100.
= 99x100x101
B = 99x100x101 : 3
= 333300
nhanh k minh
B= 1x2+3x4+5x6+...+99x100
=> Bx3= 1x2x3 + 2x3x3 + 3x4x3 + 4x5x3 + ...+ 99x100x3
=> Bx3= 1x2x3 + 2x3x(4-1) + 3x4x(5-2) + 4x5x(6-3)+...+99x100x(101-98)
=> Bx3= 1x2x3 + 2x3x4 - 1x2x3 + 3x4x5 - 2x3x4 +4x5x6 - 3x4x5 +...+ 99x100x101 - 98x99x100
=> Bx3= 99x100x101
=> B= 99x100x101:3
=> B= 333300
![](https://rs.olm.vn/images/avt/0.png?1311)
ban vt sai dau bai roi phai la
1/2+1/6+1/12+....+1/(x+1).x=2016/2017
1/1.2+1/2.3+1/3.4+.....+1/x.(x+1)=2016/2017
1-1/2+1/2-1/3+......+1/x-1/x+1=2016/2017
1-1/x+1=2016/2017
1/x+1=1-2016/2017
1/x+1=1/2017
=>x+1=2017
=>x=2016
b)
85/8:x+(-4)/17:x+15:51=4/11
85/8:x+(-4)/17:x=13/187
1413/136:x=13/187
x=15543/104
![](https://rs.olm.vn/images/avt/0.png?1311)
sao bạn lại ngăn cách giữa các số vậy,nó là -713845 hay là -71 x 38 x 45
![](https://rs.olm.vn/images/avt/0.png?1311)
câu này dễ mà chỉ là nhiều bước thôi
bạn dùng máy tính mà tính cho nhanh
chúc bạn may mắn và hoc tốt!))>♡♥♡♥♡
![](https://rs.olm.vn/images/avt/0.png?1311)
\(11M=\frac{11^6+11}{11^6+1}=\frac{11^6+1+10}{11^6+1}=\frac{11^6+1}{11^6+1}+\frac{10}{11^6+1}=1+\frac{10}{11^6+1}\)
\(11N=\frac{11^7+11}{11^7+1}=\frac{11^7+1+10}{11^7+1}=\frac{11^7+1}{11^7+1}+\frac{10}{11^7+1}=1+\frac{10}{11^7+1}\)
vì \(\frac{10}{11^6+1}>\frac{10}{11^7+1}\)
nên\(11M>11N\)
=>\(M>N\)
\(M=\frac{11^5+1}{11^6+1}\)
\(\Rightarrow11M=11.\frac{11^5+1}{11^6+1}=\frac{11^6+11}{11^6+1}=\frac{11^6+1+10}{11^6+1}=1+\frac{10}{11^6+1}\)
\(N=\frac{11^6+1}{11^7+1}\)
\(\Rightarrow11N=11.\frac{11^6+1}{11^7+1}=\frac{11^7+11}{11^7+1}=\frac{11^7+1+10}{11^7+1}=1+\frac{10}{11^7+1}\)
Do \(1+\frac{10}{11^6+1}>1+\frac{10}{11^7+1}\)
\(\Rightarrow11M>11N\)
\(\Rightarrow M>N\)
![](https://rs.olm.vn/images/avt/0.png?1311)
2^300=2^4.75=(2^4)^75=16^75
3^225=3^3.75=(3^3)^75=27^75
Vì 16^75 < 27^75
=> 2^300 < 3^225
Ta có :
\(2^{300}=2^{4.75}=\left(2^4\right)^{75}=16^{75}\)
\(3^{225}=3^{3.75}=\left(3^3\right)^{75}=27^{75}\)
Mà \(16^{75}< 27^{75}\) \(\Rightarrow\) \(2^{300}< 3^{225}\)
2011+5[300-(17-7)²]
=2011+5[300-02]
=2011+5[300-0]
=2011+5.300
=2011+1500
=3511
hk tốt
\(2011+5\left[300-\left(17-7\right)^2\right]=2011+5\left(300-10^2\right)\)
\(=2011+5\cdot200=2011+1000=3011\)