1.Tìm x, biết:\(\left|\frac{5}{3}-x\right|\)- \(\left|\frac{-5}{6}\right|\)= \(\frac{-5}{9}\)
2.Tìm số nguyên x, biết: \(\frac{\sqrt{49}}{6}\) < \(\left|x-\frac{2}{3}\right|\)< \(\frac{26}{\sqrt{81}}\)
Tìm x biết:
a) \(\frac{1}{4}+\frac{1}{3}:2x=-5\)
b) \(\left(3x-\frac{1}{4}\right).\left(x+\frac{1}{2}\right)=0\)
c) \(|x+\frac{1}{5}|-\frac{1}{2}=\frac{9}{10}\)
d) \(\sqrt{0,81}.\left(\sqrt{x}+\sqrt{\frac{16}{49}}\right)=\frac{9}{10}\)
f) \(|\frac{1}{3}.\sqrt{x+1}-\frac{2}{9}|-\frac{1}{6}=\frac{1}{9}\)
a) \(\frac{1}{4}+\frac{1}{3}:2x=-5\)
\(\frac{1}{3}:2x=\frac{-21}{4}\)
\(2x=\frac{-4}{63}\)
\(x=\frac{2}{63}\)
b) \(\left(3x-\frac{1}{4}\right)\left(x+\frac{1}{2}\right)=0\)
\(\Rightarrow\orbr{\begin{cases}3x-\frac{1}{4}=0\\x+\frac{1}{2}=0\end{cases}}\)
\(\Rightarrow\orbr{\begin{cases}x=\frac{1}{12}\\x=\frac{-1}{2}\end{cases}}\)
Vậy.........
c) \(\left|x+\frac{1}{5}\right|-\frac{1}{2}=\frac{9}{10}\)
\(\left|x+\frac{1}{5}\right|=\frac{7}{5}\)
\(\Rightarrow\orbr{\begin{cases}x+\frac{1}{5}=\frac{7}{5}\\x+\frac{1}{5}=\frac{-7}{5}\end{cases}}\)
\(\Rightarrow\orbr{\begin{cases}x=\frac{6}{5}\\x=\frac{-8}{5}\end{cases}}\)
Vậy.........
Tìm x biết :
\(\left[\frac{6:\frac{3}{5}-1\frac{1}{16}.\frac{6}{7}}{4\frac{1}{5}.\frac{10}{11}+5\frac{2}{11}}-\frac{\left(\frac{3}{20}+\frac{1}{2}-\frac{1}{15}\right).\frac{12}{49}}{3\frac{1}{3}+\frac{2}{9}}\right].x=2\frac{23}{96}\)
\(x=\frac{903}{391}\)
Bài này sử dụng MTCT đó bạn!
Tìm x biết :
a)\(\frac{3}{2}x-\frac{1}{2}=\frac{2}{5}\) b)\(\frac{4}{5}-\left|x-\frac{2}{3}\right|=\frac{2}{3}\)
c)\(x=\left(2-\frac{15}{7}\right)^2+\left|\frac{-6}{7}\right|+\frac{\sqrt{36}}{49}\)
d)\(x=\frac{16^3.3^{10}+120.6^9}{4^6.3^{12}+6^{11}}\)
Các bn lm nhah giúp mik
thanks
Tìm x, biết :
a, \(60\%x+0,4x+x:3=2\)
b, \(\left|2x-5\right|-7=\left(\frac{1}{49}-\frac{1}{3^2}\right)\left(\frac{1}{49}-\frac{1}{4^2}\right)...\left(\frac{1}{49}-\frac{1}{2015^2}\right)\)
c, \(\frac{x+1}{1}+\frac{2x+3}{3}+\frac{3x+5}{5}+...+\frac{20x+39}{39}=22+\frac{4}{3}+\frac{6}{5}+...+\frac{40}{39}\)
a. 60%x + 0,4x + x : 3 = 2
0.6x + 0,4x + x : 3 = 2
x(0,6 + 0,4 : 3 ) = 2
\(x.\frac{1}{3}=2=>x=2:\frac{1}{3}=\frac{1}{6}\)
câu B tự làm nha .
1. Tính hợp lí :
a) \(\frac{3}{4}-0,25-\left[\frac{7}{3}+\left(\frac{-9}{2}\right)\right]-\frac{5}{6}\)
b) 7 + \(\left(\frac{7}{12}-\frac{1}{2}+3\right)-\left(\frac{1}{12}+5\right)\)
2. Tìm các sô nguyên x biết:
\(\frac{3}{4}-\frac{5}{6}\le\frac{x}{12}< 1-\left(\frac{2}{3}-\frac{1}{4}\right)\)
Câu 1:
a)\(\frac{3}{4}-0,25-\left[\frac{7}{3}+\left(-\frac{9}{2}\right)\right]-\frac{5}{6}\)
\(=\frac{3}{4}-\frac{1}{4}-\frac{14}{6}+\frac{27}{6}-\frac{5}{6}\)
\(=\frac{1}{2}-\frac{4}{3}\)
\(=-\frac{5}{6}\)
b)\(7+\left(\frac{7}{12}-\frac{1}{2}+3\right)-\left(\frac{1}{12}+5\right)\)
\(=7+\frac{1}{12}+3-\frac{1}{12}-5\)
\(=5\)
Câu 2:
\(\frac{3}{4}-\frac{5}{6}\le\frac{x}{12}< 1-\left(\frac{2}{3}-\frac{1}{4}\right)\)
\(-\frac{1}{12}\le\frac{x}{12}< 1-\frac{5}{12}\)
\(-\frac{1}{12}\le\frac{x}{12}< \frac{7}{12}\)
Vậy -1\(\le\)x<7
Tìm số nguyên x biết
\(\frac{\sqrt{49}}{6}< \left|x-\frac{2}{3}\right|< \frac{26}{\sqrt{81}}\)
\(\Rightarrow\frac{7}{6}< |x-\frac{2}{3}|< \frac{26}{9}\)
\(\Rightarrow\frac{21}{18}< |x-\frac{2}{3}|< \frac{52}{18}\)
Rùi tự thay vào
\(\frac{\sqrt{49}}{6}< \left|x-\frac{2}{3}\right|< \frac{26}{\sqrt{81}}\)
\(\Leftrightarrow\frac{7}{6}< \left|x-\frac{2}{3}\right|< \frac{26}{9}\)
\(\Leftrightarrow\frac{7}{6}< 2\le\left|x-\frac{2}{3}\right|\le2< \frac{26}{9}\)
\(\Leftrightarrow\left|x-\frac{2}{3}\right|=2\)
\(\Leftrightarrow\orbr{\begin{cases}x-\frac{2}{3}=2\\x-\frac{2}{3}=-2\end{cases}}\)
\(\Leftrightarrow\orbr{\begin{cases}x=\frac{8}{3}\\x=--\frac{4}{3}\end{cases}}\)
Vậy \(x\in\left\{\frac{8}{3};-\frac{4}{3}\right\}\)
Tìm số nguyên x, biết rằng: \(\frac{3}{7}.15\frac{1}{3}+\frac{3}{7}.5\frac{2}{5}\le x\le\left(3\frac{1}{2}:7-6\frac{1}{2}\right).\left(-2\frac{1}{3}\right)\)
\(\frac{3}{7}\cdot15\cdot\frac{1}{3}+\frac{3}{7}\cdot5\cdot\frac{2}{5}\le x\le\left(3\frac{1}{2}:7-6\frac{1}{2}\right)\cdot\left(-2\frac{1}{3}\right)\)
\(\Leftrightarrow\frac{15}{7}+\frac{6}{7}\le x\le-6\cdot\frac{-5}{3}\)
\(\Leftrightarrow3\le x\le10\)
Mà \(x\in Z\)
\(\Rightarrow x\in\left\{4;5;6;7;8;9\right\}\)
bn Quân sai rồi, hỗn số \(15\frac{1}{3}\)chứ có phải \(15.\frac{1}{3}\)đâu???
\(\frac{3}{7}\cdot15\frac{1}{3}+\frac{3}{7}\cdot5\frac{2}{5}\le x\le\left(3\frac{1}{2}:7-6\frac{1}{2}\right)\cdot\left(-2\frac{1}{3}\right)\)
\(\Rightarrow\frac{3}{7}\left(15\frac{1}{3}+5\frac{2}{5}\right)\le x\le\left(\frac{7}{2}:7-\frac{13}{2}\right)\cdot\left(-\frac{7}{3}\right)\)
\(\Rightarrow\frac{3}{7}\left(\frac{46}{3}+\frac{27}{5}\right)\le x\le\left(\frac{7}{14}-\frac{13}{2}\right)\cdot\left(-\frac{7}{3}\right)\)
\(\Rightarrow\frac{311}{35}\le x\le14\)
\(\Rightarrow8,8...\le x\le14\)
Đến đây là tìm x :))
Tìm x biết
a) (8-5x).(x+2)+4.(x-2).(x+1)+2.(x-2).(x+2)=0
b)\(\left(-\frac{2}{5}+x\right):\frac{7}{9}+\left(-\frac{3}{5}+\frac{5}{6}\right):\frac{7}{9}=0\)
c)\(1+\frac{1}{3}+\frac{1}{6}+\frac{1}{10}+...+\frac{2}{x\left(x+1\right)}=1\frac{2003}{2004}\)
Tìm số nguyên x, nếu biết
\(\frac{^{2^{4-x}}}{16^5}=32^6\)
\(\frac{3^{2x+3}}{9^3}=9^{14}\)
\(\left(-2\right)^x=-\frac{\left(-8^4\right)}{\left(-32\right)^3}\)
\(\left(-5^x\right)=\frac{25^{10}}{\left(-5\right)^{17}}\)
\(\frac{2^{4-x}}{16^5}=32^6\)
=> \(\frac{2^{4-x}}{\left(2^4\right)^5}=\left(2^5\right)^6\)
=> \(\frac{2^{4-x}}{2^{20}}=2^{30}\)
=> \(2^{4-x}=2^{30}.2^{20}\)
=> \(2^{4-x}=2^{50}\)
=> 4 - x = 50
=> x = 4 - 50 = -46
\(\frac{3^{2x+3}}{9^3}=9^{14}\)
=> \(\frac{3^{2x+3}}{\left(3^2\right)^3}=\left(3^2\right)^{14}\)
=> \(\frac{3^{2x+3}}{3^6}=3^{28}\)
=> \(3^{2x+3}=3^{28}.3^6\)
=> \(3^{2x+3}=3^{34}\)
=> 2x + 3 = 34
=> 2x = 34 - 3
=> 2x = 31
=> x = 31/2