Viết sơ đồ về câu lệnh lặp for....do

Mong mọi người giúp mình xin cảm ơn nhiều ạ

\(\frac{1}{x-3}+2=\frac{5}{x-1}+x\)

\(\frac{1}{x^2+2x+3}+4=\frac{1}{x^2+1}\)

\(\frac{4}{-25x^2+20x-3}=\frac{3}{5x-1}-\frac{2}{5x-3}\)

\(\frac{1}{x^2-3x+2}+\frac{1}{x^2-5x+6}-\frac{2}{x^2-4x+3}=0\)

\(\frac{x-1}{2x^2-4x}-\frac{7}{8x}=\frac{5-x}{4x^2-8x}-\frac{1}{8x-16}\)

\(\frac{1}{x^2+9x+20}+\frac{1}{x^2+11x+30}+\frac{1}{x^2+13x+42}=\frac{1}{18}\)

1/3 + 1/6 + 1/10 + ... + 1/x ( x +1 ) = 1999/2001

=> 2/6 + 2/12 + 2/20 + .. + 2/ x ( x+1 )= 1999/2001

=> 2 ( 1/6 + 1/12 + ..+ 1/ x ( x +1 ) ) = 1999/2001

=> 2 ( 1/2 x 3 + 1/ 3 x 4 + ... + 1/x ( x + 1 ) ) = 1999/2001

=> 2 ( 1/2 - 1/3 + 1/3 - 1/4 + .. + 1/x - 1/ ( x+1 ) ) = 1999/2001

=> 2 ( 1/2 - 1/ ( x+ 1 ) ) = 1999/2001 => 1/2 - 1/ ( x + 1 ) = 1999/2001 : 2

=>  1/ x + 1 = 1/2 - 1999/2001 : 2 = 1/2001 => x + 1 = 2001 => x = 2000