a, 1 phần 5-2 phần 3 nhân x=1 b, /x-1 phần 4/=1 phần 5 c,x/-8=-3/4=15/y 16/11/2021 Bởi Lydia a, 1 phần 5-2 phần 3 nhân x=1 b, /x-1 phần 4/=1 phần 5 c,x/-8=-3/4=15/y
Đáp án: c. \(\left\{ \begin{array}{l}x = 6\\y = – 20\end{array} \right.\) Giải thích các bước giải: \(\begin{array}{l}a.\frac{1}{5} – \frac{2}{3}x = 1\\ \to \frac{2}{3}x = \frac{1}{5} – 1 = \frac{{ – 4}}{5}\\ \to x = – \frac{4}{5}:\frac{2}{3} = – \frac{4}{5}.\frac{3}{2}\\ \to x = – \frac{6}{5}\\b.\left| {\frac{{x – 1}}{4}} \right| = \frac{1}{5}\\ \to \left[ \begin{array}{l}\frac{{x – 1}}{4} = \frac{1}{5}\\\frac{{x – 1}}{4} = – \frac{1}{5}\end{array} \right.\\ \to \left[ \begin{array}{l}5x – 5 = 4\\5x – 5 = – 4\end{array} \right.\\ \to \left[ \begin{array}{l}5x = 9\\5x = 1\end{array} \right.\\ \to \left[ \begin{array}{l}x = \frac{9}{5}\\x = \frac{1}{5}\end{array} \right.\\c.\left\{ \begin{array}{l}\frac{x}{{ – 8}} = – \frac{3}{4}\\ – \frac{3}{4} = \frac{{15}}{y}\left( {y \ne 0} \right)\end{array} \right.\\ \to \left\{ \begin{array}{l}x = \frac{3}{4}.8\\3y = – 60\end{array} \right.\\ \to \left\{ \begin{array}{l}x = 6\\y = – 20\end{array} \right.\end{array}\) Bình luận
Đáp án: a,1/5×2/3-x1 =2/15×1 =2/15 b,x-1/4=1/5 =x-1:4=5x-1=5×4 x-1=20 x=20+1=21 c,x/8=3/4=15/y Bình luận
Đáp án:
c. \(\left\{ \begin{array}{l}
x = 6\\
y = – 20
\end{array} \right.\)
Giải thích các bước giải:
\(\begin{array}{l}
a.\frac{1}{5} – \frac{2}{3}x = 1\\
\to \frac{2}{3}x = \frac{1}{5} – 1 = \frac{{ – 4}}{5}\\
\to x = – \frac{4}{5}:\frac{2}{3} = – \frac{4}{5}.\frac{3}{2}\\
\to x = – \frac{6}{5}\\
b.\left| {\frac{{x – 1}}{4}} \right| = \frac{1}{5}\\
\to \left[ \begin{array}{l}
\frac{{x – 1}}{4} = \frac{1}{5}\\
\frac{{x – 1}}{4} = – \frac{1}{5}
\end{array} \right.\\
\to \left[ \begin{array}{l}
5x – 5 = 4\\
5x – 5 = – 4
\end{array} \right.\\
\to \left[ \begin{array}{l}
5x = 9\\
5x = 1
\end{array} \right.\\
\to \left[ \begin{array}{l}
x = \frac{9}{5}\\
x = \frac{1}{5}
\end{array} \right.\\
c.\left\{ \begin{array}{l}
\frac{x}{{ – 8}} = – \frac{3}{4}\\
– \frac{3}{4} = \frac{{15}}{y}\left( {y \ne 0} \right)
\end{array} \right.\\
\to \left\{ \begin{array}{l}
x = \frac{3}{4}.8\\
3y = – 60
\end{array} \right.\\
\to \left\{ \begin{array}{l}
x = 6\\
y = – 20
\end{array} \right.
\end{array}\)
Đáp án:
a,1/5×2/3-x1
=2/15×1
=2/15
b,x-1/4=1/5
=x-1:4=5x-1=5×4
x-1=20
x=20+1=21
c,x/8=3/4=15/y