tinh 1+(1+2)+(1+2+3)+...+(1+2+3+...+100)
tinh S= 1+1/2(1+2)+1/3(1+2+3)+...+1/100(1+2+3+...+100)
Tinh
A=1+1/2(1+2)+1/3(1+2+3)+...+1/100(1+2+3+...+100)
A = 1 + \(\frac{1}{2}\left(1+2\right)\)+ \(\frac{1}{3}\left(1+2+3\right)\)+ .... + \(\frac{1}{100}\left(1+2+3+...+100\right)\)
A = \(1+\frac{1}{2}\cdot\frac{2.3}{2}+\frac{1}{3}\cdot\frac{3.4}{2}+...+\frac{1}{100}\cdot\frac{100.101}{2}\)
A = \(\frac{2}{2}+\frac{3}{2}+\frac{4}{2}+...+\frac{101}{2}\)
A = \(\frac{2+3+4+...+101}{2}\)
A = \(\frac{\left(101+2\right).100}{2}\div2\)
A = \(5150\div2=2575\)
tinh A=1+ 1/2 +1/(2*3) +1/(3*4)+...+1/(99*100)+100
tinh
A=1/1+2+1/1+2+3+1/1+2+3+4+...................+1/1+2+3+4+...............+100
Tinh [1\2^2-1].[1\3^2-1]....[1\100^2-1]
A=99-(1/2 + 1/3+1/4+...+1/100) : (1/2+2/3+3/4+...+99/100)
tinh gia tri cua A.
tinh B = 3+3/(1+2)+3/(1+2+3)+...+3/(1+2+3+...+100)
tinh A=1/2+1/2^2+1/2^3+.....+1/2^100
\(A=\frac{1}{2}+\frac{1}{2^2}+\frac{1}{2^3}+...+\frac{1}{2^{100}}\)
\(2A=1+\frac{1}{2}+\frac{1}{2^2}+...+\frac{1}{2^{99}}\)
\(2A-A=1-\frac{1}{2^{100}}\)
\(A=1-\frac{1}{2^{100}}\)
tinh 1-1/2^2.1-1/3^2.....1-1/100^2