tìm x \(0,2:1\frac{1}{5}=\frac{2}{3}:\left(6x+7\right)\)
Tìm x
\(0,2:1\frac{1}{5}=\frac{2}{3};\left(6x+7\right)\)
Eh, cho mk sửa: dấu chấm phẩy là mk viết nhầm phải là dấu Chia
tìm x
a) \(3\frac{1}{3}:1\frac{1}{3}=26:\left(2x-1\right)\)
b)0,2:\(1\frac{1}{5}=\frac{2}{3}:\left(6x+7\right)\)
Tìm số hữu tỉ x trong tỉ lệ thức :
a ) 0,4 ; x = x : 0,9
b ) \(13\frac{1}{3}:1\frac{1}{3}=26:\left(2x-1\right)\)
c ) \(0,2:1\frac{1}{5}=\frac{2}{3}:\left(6x+7\right)\)
d ) \(\frac{37-x}{x+13}=\frac{3}{7}\)
TÌm số hữu tỉ x trong tỉ lệ thức:
a) 0,4 : x = x : 0,9
b) \(13\frac{1}{3}:1\frac{1}{3}=26:\left(2x-1\right)\)
c) \(0,2:1\frac{1}{5}=\frac{2}{3}:\left(6x+7\right)\)
d) \(\frac{37-x}{x+13}=\frac{3}{7}\)
a, 0,4 : x = x : 0,9
<=> x2 = 0,4 . 0,9
<=> x2 = 0,36
<=> x = 0,6 hoặc -0,6
b, \(13\frac{1}{3}\div1\frac{1}{3}=26\div\left(2x-1\right)\)
\(\Leftrightarrow\frac{40}{3}\div\frac{4}{3}=26\div\left(2x-1\right)\)
\(\Leftrightarrow10=26\div\left(2x-1\right)\)
\(\Leftrightarrow2x-1=\frac{13}{5}\)
\(\Leftrightarrow2x=\frac{18}{5}\)
\(\Leftrightarrow x=\frac{9}{5}\)
c, \(0,2\div1\frac{1}{5}=\frac{2}{3}\div\left(6x+7\right)\)
\(\Leftrightarrow\frac{1}{5}\div\frac{6}{5}=\frac{2}{3}\div\left(6x+7\right)\)
\(\Leftrightarrow\frac{1}{6}=\frac{2}{3}\div\left(6x+7\right)\)
\(\Leftrightarrow6x+7=4\)
\(\Leftrightarrow6x=-3\)
\(\Leftrightarrow x=\frac{-1}{2}\)
d, \(\frac{37-x}{x+13}=\frac{3}{7}\)
\(\Leftrightarrow7\left(37-x\right)=3\left(x+13\right)\)
\(\Leftrightarrow259-7x=3x+39\)
\(\Leftrightarrow-10x=-220\)
\(\Leftrightarrow x=22\)
Tìm số hữu tỉ x trong các tỉ lệ thức :
a ) 0,4 : x = x : 0,9
b )\(13\frac{1}{3}:1\frac{1}{3}=26:\left(2x-1\right)\)
c ) \(0,2:1\frac{1}{5}=\frac{2}{3}:\left(6x+7\right)\)
d ) \(\frac{37x}{x+13}=\frac{3}{7}\)
a, x=0,6
b,x=1,8
c,x=-0,5
d,x=\(\frac{39}{256}\)
Tìm x:
\(\frac{2x-3}{\left(7-6x\right)^2}+\frac{x-2}{\left(7-6x\right)^2}=\frac{6x-3}{\left(3x-5\right)^2}-\frac{12x-10}{\left(3x-5\right)^2}\)
\(\frac{2x-3}{\left(7-6x\right)^2}+\frac{x-2}{\left(7-6x\right)^2}=\frac{6x-3}{\left(3x-5\right)^2}-\frac{12x-10}{\left(3x-5\right)^2}\)
\(\Leftrightarrow\frac{2x-3+x-2}{\left(7-6x\right)^2}=\frac{6x-3-12x+10}{\left(3x-5\right)^2}\)
\(\Leftrightarrow\frac{3x-5}{\left(7-6x\right)^2}=\frac{7-6x}{\left(3x-5\right)^2}\)
\(\Leftrightarrow\left(7-6x\right)^3=\left(3x-5\right)^3\)
\(\Leftrightarrow7-6x=3x-5\)
\(\Leftrightarrow7+5=3x+6x\)
\(\Leftrightarrow12=9x\)
\(\Leftrightarrow x=\frac{4}{3}\)
Vậy \(x=\frac{4}{3}\)
Câu 1:Tìm x biết:
a,\(0,2\div1\frac{1}{5}=\frac{2}{3}\div\left(6x+7\right)\)
b,\(13\frac{1}{3}\div1\frac{1}{3}=26\div\left(2x-1\right)\)
Câu 2:Tìm x  Z để biểu thức P có giá trị nguyên :
a, P=\(\frac{5}{\sqrt{x-1}}\)
b, P=\(\frac{7}{\sqrt{x-1}}\)
Tìm x , y :
\(\frac{1}{3}\left|\frac{1}{4}x-\frac{1}{5}\right|+\frac{3}{7}\left|\frac{x}{y}-0,2\right|=0\)
\(\frac{1}{3}\left|\frac{1}{4}x-\frac{1}{5}\right|+\frac{3}{7}\left|\frac{x}{y}-0,2\right|=0\)
Nhận xét : \(\left|\frac{1}{4}x-\frac{1}{5}\right|\ge0\)với \(\forall x\)(vì giá trị tuyệt đối không âm)
\(\Rightarrow\frac{1}{3}\left|\frac{1}{4}x-\frac{1}{5}\right|\ge0\)(1)
\(\left|\frac{x}{y}-0,2\right|\ge0\)với \(\forall x\),\(\left(y\ne0\right)\)(vì giá trị tuyệt đối không âm)
\(\Rightarrow\frac{3}{7}\left|\frac{x}{y}-0,2\right|\ge0\) (2)
Từ (1) và (2) => \(\frac{1}{3}\left|\frac{1}{4}x-\frac{1}{5}\right|+\frac{3}{7}\left|\frac{x}{y}-0,2\right|\ge0\)
Để \(\frac{1}{3}\left|\frac{1}{4}x-\frac{1}{5}\right|+\frac{3}{7}\left|\frac{x}{y}-0,2\right|=0\)
\(\Leftrightarrow\hept{\begin{cases}\frac{1}{3}\left|\frac{1}{4}x-\frac{1}{5}\right|=0\\\frac{3}{7}\left|\frac{x}{y}-0,2\right|=0\end{cases}\Leftrightarrow}\hept{\begin{cases}\left|\frac{1}{4}x-\frac{1}{5}\right|=\frac{1}{3}\\\left|\frac{x}{y}-0,2\right|=\frac{3}{7}\end{cases}}\Leftrightarrow\hept{\begin{cases}\frac{1}{4}x-\frac{1}{5}=0\\\frac{x}{y}-0,2=0\end{cases}}\)
\(\Leftrightarrow\hept{\begin{cases}\frac{1}{4}x=\frac{1}{5}\\\frac{x}{y}=0,2\end{cases}\Leftrightarrow}\hept{\begin{cases}x=\frac{4}{5}\\\frac{4}{5}\div y=0,2\end{cases}\Leftrightarrow}\hept{\begin{cases}x=\frac{4}{5}\\y=4\left(tm\right)\end{cases}}\)
Vậy \(x=\frac{4}{5};y=4\) (Tm)
1) Tính ( nhanh nếu có thể )
a) \(\frac{15}{34}-\frac{1}{3}+\frac{19}{34}-1\frac{5}{7}-\frac{2}{3}\)
b) 3,5 + 4,2 + \(\frac{4}{5}\)+ (-4,2) + (-3,5)
2) Tìm x biết
a) 0,2 : \(1\frac{1}{5}=\frac{2}{3}:\left(6x+7\right)\)
b) \(13\frac{1}{13}:\frac{1}{13}=26:\left(2x-1\right)\)