\(\frac{3x}{4.7}+\frac{3x}{7.10}+\frac{3x}{10.13}+\frac{3x}{13.16}+...+\frac{3x}{19.22}=\frac{-5}{88}\)
\(\left(\frac{3}{4.7}+\frac{3}{7.10}+\frac{3}{10.13}+\frac{3}{13.16}+...+\frac{3}{19.22}\right)x=\frac{-5}{88}\)
\(\left(\frac{1}{4}-\frac{1}{7}+\frac{1}{7}-\frac{1}{10}+\frac{1}{10}-\frac{1}{13}+\frac{1}{13}-\frac{1}{16}+...+\frac{1}{19}-\frac{1}{22}\right)x=\frac{-5}{88}\)
\(\left[\frac{1}{4}+\left(\frac{1}{7}-\frac{1}{7}\right)+\left(\frac{1}{10}-\frac{1}{10}\right)+...+\left(\frac{1}{19}-\frac{1}{19}\right)-\frac{1}{22}\right]x=\frac{-5}{88}\)
\(\left[\frac{1}{4}-\frac{1}{22}\right]x=\frac{-5}{88}\)
\(\frac{9}{44}x=\frac{-5}{88}\)
\(x=\frac{-5}{88}:\frac{9}{44}\)
\(x=\frac{-5}{18}\)
~ Hok tốt ~
#)Giải :
Đặt \(A=\frac{3x}{2.7}+\frac{3x}{7.10}+\frac{3x}{10.13}+\frac{3x}{13.16}+...+\frac{3x}{19.22}=-\frac{5}{88}\)
\(A=\frac{3x}{2}+\frac{3x}{7}-\frac{3x}{7}+\frac{3x}{10}-\frac{3x}{10}+\frac{3x}{13}-\frac{3x}{13}+\frac{3x}{16}-...-\frac{3x}{19}+\frac{3x}{22}=-\frac{5}{88}\)
\(A=\frac{3x}{2}+0+0+0+...+0+\frac{3x}{22}=-\frac{5}{88}\)
\(A=\frac{3x}{2}+\frac{3x}{22}=-\frac{5}{88}\)
\(3x:\left(2+22\right)=-\frac{5}{88}\)
\(3x:24=-\frac{5}{88}\)
\(3x=-\frac{5}{88}.24\)
\(3x=-\frac{7}{11}\)
\(x=-\frac{7}{11}:3\)
\(x=-\frac{7}{33}\)
#~Will~be~Pens~#
