\(\frac{x}{5}\)-\(\frac{5}{2}\)=-31
tìm x biết
a)\(\frac{x}{5}-\frac{5}{2}=31\)
b)\(\frac{x}{5}-\frac{5}{2}=-31\)
chỉ cần kết quả thôi
Kết quả ko thì nhanh thôi !
\(\left(a\right)\frac{x}{5}-\frac{5}{2}=31\)
\(x=167\frac{1}{2}\)
\(\left(b\right)\frac{x}{5}-\frac{5}{2}=-31\)
\(x=-142\frac{1}{2}\)
k nhé !
a) Gọi 3 số cần tìm lần lượt là x;y;z. Ta có:
\(\hept{\begin{cases}\frac{x}{2}=\frac{y}{3}=\frac{z}{5}\\x+y+z=310\end{cases}}\)
\(\hept{\begin{cases}\frac{x}{2}=\frac{y}{3}=\frac{z}{5}=\frac{x+y+z}{2+3+5}=\frac{310}{10}=31\\x+y+z=310\end{cases}}\)
\(\hept{\begin{cases}\frac{x}{2}=31\\\frac{y}{3}=31\\\frac{z}{5}=31\end{cases}}\)
\(\hept{\begin{cases}x=62\\y=93\\z=155\end{cases}}\)
Tìm số nguyên x
a) \(\frac{1}{3}+\frac{-2}{5}+\frac{1}{6}+\frac{-1}{5}\le x< \frac{-3}{4}+\frac{2}{7}+\frac{-1}{4}+\frac{3}{5}+\frac{5}{7}\)
b)\(\frac{5}{17}+\frac{-9}{4}+\frac{-26}{31}+\frac{12}{17}+\frac{-11}{31}< \frac{x}{9}\le\frac{-3}{7}+\frac{7}{15}+\frac{4}{-7}+\frac{8}{15}\)
\(a)\frac{1}{3}+\frac{-2}{5}+\frac{1}{6}+\frac{-1}{5}\le x< \frac{-3}{4}+\frac{2}{7}+\frac{-1}{4}+\frac{3}{5}+\frac{5}{7}\)
\(\Rightarrow\frac{1}{3}+\frac{1}{6}+\frac{-2}{5}+\frac{-1}{5}\le x< \frac{-3}{4}+\frac{-1}{4}+\frac{2}{7}+\frac{5}{7}+\frac{3}{5}\)
\(\Rightarrow\frac{2}{6}+\frac{1}{6}+\frac{-3}{5}\le x< -1+1+\frac{3}{5}\)
\(\Rightarrow\frac{1}{2}+\frac{-3}{5}\le x< \frac{3}{5}\)
\(\Rightarrow\frac{-1}{10}\le x< \frac{6}{10}\)
\(\Rightarrow-1\le x< 6\)
\(\Rightarrow x\in\left\{-1;0;1;2;3;4;5\right\}\)
Bài b tương tự
bạn ơi bạn giải câu b được ko. mk ko biết làm câu b
Tìm X:
\(X-\left(\frac{31}{5}+\frac{31}{15}+\frac{31}{35}+\frac{31}{63}+\frac{31}{99}+\frac{31}{143}\right)=\frac{9}{13}\)
\(X-\left(\frac{31}{5}+\frac{31}{15}+\frac{31}{35}+\frac{31}{63}+\frac{31}{99}+\frac{31}{143}\right)=\frac{9}{13}\)
\(X-\left(\frac{31}{5}+\frac{31}{3\cdot5}+\frac{31}{5\cdot7}+\frac{31}{7\cdot9}+\frac{31}{9\cdot11}+\frac{31}{11\cdot13}\right)=\frac{9}{13}\)
\(X-\left[\frac{31}{2}\cdot\left(\frac{1}{3}-\frac{1}{5}+\frac{1}{5}-\frac{1}{7}+\frac{1}{7}-\frac{1}{9}+\frac{1}{9}-\frac{1}{11}+\frac{1}{11}-\frac{1}{13}\right)+\frac{31}{5}\right]=\frac{9}{13}\)
\(X-\left[\frac{31}{2}\cdot\left(\frac{1}{3}-\frac{1}{13}\right)+\frac{31}{5}\right]=\frac{9}{13}\)
\(X-\left[\frac{31}{2}\cdot\frac{10}{39}+\frac{31}{5}\right]=\frac{9}{13}\)
\(X-\frac{1984}{195}=\frac{9}{13}\)
\(\Rightarrow X=\frac{9}{13}+\frac{1984}{195}=\frac{163}{15}\)
Tìm x biết:
a.
\(\frac{1}{4}.\frac{2}{6}.\frac{3}{8}.\frac{4}{10}.\frac{5}{12}...\frac{30}{62}.\frac{31}{64}=2^x\)
b.
\(\frac{4^5+4^5+4^5+4^5}{3^5+3^5+3^5}.\frac{6^5+6^5+6^5+6^5+6^5+6^5}{2^5+2^5}=2^x\)
\(\frac{1}{4}\cdot\frac{2}{6}\cdot\frac{3}{8}\cdot\frac{4}{10}\cdot....\cdot\frac{30}{62}\cdot\frac{31}{64}=2^x\)
\(\Leftrightarrow\frac{1}{2}\left(\frac{1}{2}\cdot\frac{2}{3}\cdot\frac{3}{4}\cdot.....\cdot\frac{30}{31}\cdot\frac{31}{32}\right)=2^x\)
\(\Leftrightarrow\frac{1}{32}=2^{x+1}\)
Làm nốt.
ko làm được câu này hay câu b ib với tớ nha.khẳng định tối giải.
tìm x
\(4\frac{5}{9}:2\frac{5}{18}-7< x< \left(3\frac{1}{5}:3,2+4,5\times1\frac{31}{45}\right):\left(-21\frac{1}{2}\right)\)
Tính lần lượt 2 vế ta được:
-5 < x< -0,4
=> x = -4, -3, -2, -1, 0
A)\(\frac{1}{4}.\frac{2}{6}.\frac{3}{8}.\frac{4}{10}.\frac{5}{12}....\frac{30}{62}.\frac{31}{64}=4^x\)
B)\(\frac{4^5+4^5+4^5+4^5}{3^5+3^5+3^5}.\frac{6^5+6^5+6^5+6^5+6^5+6^5}{2^5+2^5}=8^x\)
\(4\frac{5}{9}:2\frac{5}{18}-7< x< \left(3\frac{1}{5}:3,2+4,5\cdot1\frac{31}{45}\right)=\left(-21\frac{1}{2}\right)\)
Tính X : Để A+x=B
Biết A= \(\frac{9}{40}\)và B = \(\frac{3}{3}-\frac{2}{31}-\frac{2}{41}\)/ \(\frac{5}{3}-\frac{5}{31}-\frac{5}{41}\)
B=\(\frac{2\left(\frac{1}{3}+\frac{1}{31}+\frac{1}{41}\right)}{5\left(\frac{1}{3}+\frac{1}{31}+\frac{1}{41}\right)}=\frac{2}{5}\)
thay vào ta đc
\(\frac{9}{40}+x=\frac{2}{5}\)
\(x=\frac{7}{40}\)
\(\frac{x}{4}-\frac{3}{7}+\frac{2}{5}=\frac{31}{140}\)
\(\frac{x}{4}-\frac{3}{7}+\frac{2}{5}=\frac{31}{140}\)
\(\frac{x}{4}=\frac{31}{140}-\frac{2}{5}+\frac{3}{7}\)
\(\frac{x}{4}=\frac{1}{4}\)
\(\Rightarrow x=1\)
\(\frac{x}{4}-\frac{3}{7}+\frac{2}{5}=\frac{31}{140}\)
\(\frac{x}{4}-\frac{3}{7}=\frac{31}{140}-\frac{2}{5}\)
\(\frac{x}{4}-\frac{3}{7}=-\frac{5}{28}\)
\(\frac{x}{4}=-\frac{5}{28}+\frac{3}{7}\)
\(\frac{x}{4}=\frac{1}{4}\)
\(\Rightarrow x=1\)