Ta có:
\(A=\frac{3}{2}+\frac{7}{6}+\frac{13}{12}+...+\frac{9901}{9900}\)
\(A=1+\frac{1}{2}+1+\frac{1}{6}+1+\frac{1}{12}+...+1+\frac{1}{9900}\)\(A=1+1+1+...+1(51c/s)+\frac{1}{2}+\frac{1}{6}+\frac{1}{12}+...+\frac{1}{9900}\)
\(A=51+\frac{1}{1\cdot2}+\frac{1}{2\cdot3}+\frac{1}{3\cdot4}+...+\frac{1}{99\cdot100}\)
\(A=51+1-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+\frac{1}{3}-\frac{1}{4}+...+\frac{1}{99}-\frac{1}{100}\)
\(A=51+1-\frac{1}{100}\)
\(A=52-\frac{1}{100}\)
\(A=\frac{5199}{100}\)
Cái đoạn 1+1+1+...+1 ( 51 c/s) số tớ ko thể giải thích trên máy tính đc nên bn tự suy nghĩ nhé:)))
A= 3/2+7/6+...+9901/9900
A=1+1/2+1+1/6+1+1/12+...+1/9900
A=(1+1+1+...+1)+(1/2+1/6+1/12+...+1/9900)
A=(1+1+1+...+1)+(1/1x2+1/2x3+1/3x4+...+1/99x100)
A=(1+1+1+...+1)+(1/1-1/2+1/2-1/3+1/3-1/4+1/4-...-1/99+1/99-1/100)
A=99+(1/1-1/100)
A=99+99/100
A=9999/100
A=9900/100+99
