5/11+1/2+2/5+6/11+3/4+16/25+5/16

=1441/400

19/4+37/100+1/8+132/25+5/2+37/12

=1933/120

Ban lam sao duooc nhu the giai ra cho minh voi

B= (5/2.1 + 4/1.11 + 3/11.2 )+(1/2.15 +13/15.4)

B= (55/22 + 8/22 + 3/22) + ( 2/4.15 + 13/15.4 )

B= 3 + 15/15.4 = 3+1/4 = 13/4 

bai1 tu -1738 den -16 co so cac so nguyen am la : (1738-16)/2+1=862

C1

B=1+3+5+..+99=50.(99+1)/2=50.50=2500

C=-(2+4+6+...+100)=50.(100+2)/2=50*51=-2550

A=B+C=2500-2550=-50

C2

A=1+(3-2)+(5-4)+...+(99-98)+100

=1+1+1+...+1-100

=1+49-100=-50

Ta có:

A=2+2^2+2^3+....+2^99+2^100

=>2A=2^2+2^3+2^4+....+2^100+2^101

=>2A-A=(2^2+2^3+2^4+....+2^101)-(2+2^2+2^3+....+2^99)

Phá ngoặc ra, ta được:

A=2^101-2.

P/s:Nếu bạn có máy tính cầm tay, bấm 2^100-2 bằng bao nhiêu nhé !!!Chúc bạn học tốt.

Ta có : 

\(A=2+2^2+2^3+...+2^{100}\)

\(\Rightarrow2A=2^2+2^3+2^4+...+2^{101}\)

\(\Rightarrow2A-A=\left(2^2+2^3+2^4+...+2^{100}\right)-\left(2+2^2+2^3+...+2^{100}\right)\)

\(\Rightarrow A=2^{101}-2\)

Vậy \(A=2^{101}-2\)

cam on moi nguoi nhe

\(A=1-2+3-4+...+97-98+99\)

\(A=\left(1-2\right)+\left(3-4\right)+...+\left(97-98\right)+99\)

\(A=-1+\left(-1\right)+...+\left(-1\right)+99\)

\(A=\left(-1\right).49+99\)

\(A=-49+99\)

\(A=50\)

A = 1 - 2 + 3 - 4 +…+ 97 - 98 + 99

A = ( 1 - 2 ) + ( 3 - 4 ) + ... + ( 97 - 98 ) + 99

A = ( -1 ) + ( -1 ) + ... + ( -1 ) + 99

A = ( -1 ) . 49 + 99

A = 50  

\(A=1-2+3-4+...+97-98+99\)

\(A=\left(1-2\right)+\left(3-4\right)+...+\left(97-98\right)+99\)

\(A=\left(-1\right)+\left(-1\right)+...+\left(-1\right)+99\)

\(\Rightarrow A=\left(-1\right).49+99\)

\(\Rightarrow A=50\)

ok minh se giup vao 123 nha