1 )3 2/3 x(hỗn số )+5 1/2 =11 1/6 2) 2 3/5 x-1/7 =1 9 /35(hỗn số ) 3) {3 4/5x (hỗn số)+40}:38/5=-50 4){ 5 1/2(hỗn số )-2x}.3/22=-1 1/2(hỗn số) 5)3,2x-

0 bình luận về “1 )3 2/3 x(hỗn số )+5 1/2 =11 1/6 2) 2 3/5 x-1/7 =1 9 /35(hỗn số ) 3) {3 4/5x (hỗn số)+40}:38/5=-50 4){ 5 1/2(hỗn số )-2x}.3/22=-1 1/2(hỗn số) 5)3,2x-”

1. Đáp án:

   $1)x=\frac{17}{11}\\
   2) x=\frac{7}{13}\\
   3) x=\frac{-2100}{19}\\
   4) x=\frac{33}{4}\\
   5) x=\frac{15}{64}$

   Giải thích các bước giải:

    $1)3\frac{2}{3}x+5\frac{1}{2}=11\frac{1}{6}\\
   \Leftrightarrow \frac{11}{3}x+\frac{11}{2}=\frac{67}{6}\\
   \Leftrightarrow \frac{11}{3}x=\frac{67}{6}-\frac{11}{2}\\
   \Leftrightarrow \frac{11}{3}x=\frac{67}{6}-\frac{33}{6}\\
   \Leftrightarrow \frac{11}{3}x=\frac{34}{6}\\
   \Leftrightarrow x=\frac{34}{6}.\frac{3}{11}=\frac{17}{11}\\
   2) 2\frac{3}{5}x-\frac{1}{7}=1\frac{9}{35}\\
   \Leftrightarrow \frac{13}{5}x-\frac{1}{7}=\frac{44}{35}\\
   \Leftrightarrow \frac{13}{5}x=\frac{44}{35}+\frac{1}{7}\\
   \Leftrightarrow \frac{13}{5}x=\frac{44}{35}+\frac{5}{35}\\
   \Leftrightarrow \frac{13}{5}x=\frac{49}{35}\\
   \Leftrightarrow x=\frac{49}{35}.\frac{5}{13}=\frac{7}{13}\\
   3) \left (3\frac{4}{5}x+40  \right ): \frac{38}{5}=-50\\
   \Leftrightarrow \left ( \frac{19}{5}x+40 \right ).\frac{5}{38}=-50\\
   \Leftrightarrow \frac{19}{5}x.\frac{5}{38}+\frac{40.5}{38}=-50\\
   \Leftrightarrow \frac{1}{2}x+\frac{100}{19}=-50\\
   \Leftrightarrow \frac{1}{2}x=-50-\frac{100}{19}\\
   \Leftrightarrow \frac{1}{2}x=\frac{(-50).19}{19}-\frac{100}{19}\\
   \Leftrightarrow \frac{1}{2}x=\frac{-950-100}{19}\\
   \Leftrightarrow x=\frac{-1050}{19}.2\\
   \Leftrightarrow x=\frac{-2100}{19}\\
   4) \left ( 5\frac{1}{2}-2x \right ).\frac{3}{22}=-1\frac{1}{2}\\
   \Leftrightarrow \left ( \frac{11}{2}-2x \right ).\frac{3}{22}=-\frac{3}{2}\\
   \Leftrightarrow \frac{11}{2}.\frac{3}{22}-2x\frac{3}{22}=-\frac{3}{2}\\
   \Leftrightarrow \frac{3}{4}-\frac{3}{11}x=-\frac{3}{2}\\
   \Leftrightarrow -\frac{3}{11}x=-\frac{3}{2}-\frac{3}{4}\\
   \Leftrightarrow -\frac{3}{11}x=-\frac{6}{4}-\frac{3}{4}\\
   \Leftrightarrow -\frac{3}{11}x=\frac{-9}{4}\\
   \Leftrightarrow x=\frac{9}{4}.\frac{11}{3}=\frac{33}{4}\\
   5) 3,2x-[\frac{4}{5}+\frac{2}{3}]:3\frac{2}{3}=\frac{7}{20}\\
   \Leftrightarrow 3,2x-[\frac{12}{15}+\frac{10}{15}]:\frac{11}{3}=\frac{7}{20}\\
   \Leftrightarrow 3,2x-\frac{22}{15}.\frac{3}{11}=\frac{7}{20}\\
   \Leftrightarrow 3,2x-\frac{2}{5}=\frac{7}{20}\\
   \Leftrightarrow 3,2x=\frac{2}{5}+\frac{7}{20}\\
   \Leftrightarrow 3,2x=\frac{8}{20}+\frac{7}{20}\\
   \Leftrightarrow 3,2x=\frac{15}{20}=\frac{3}{4}\\
   \Leftrightarrow x=\frac{3}{4}:3,2=\frac{15}{64}$

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