Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.
a) Ta được: x . 1,25 = 5. (-2) nên \(x = \frac{{5.( - 2)}}{{1,25}} = - 8\)
Vậy x = -8
b) Vì 18 : x = 2,4 : 3,6 nên \(\frac{{18}}{x} = \frac{{2,4}}{{3,6}} \Rightarrow 18.3,6 = x.2,4 \Leftrightarrow x = \frac{{18.3,6}}{{2,4}} = 27\)
Vậy x = 27
c) Vì (x+1) : 0,4 = 0,5 : 0,2 nên \(\frac{{x + 1}}{{0,4}} = \frac{{0,5}}{{0,2}} \Rightarrow (x + 1).0,2 = 0,4.0,5 \Leftrightarrow x + 1 = \frac{{0,4.0,5}}{{0,2}} = 1 \Leftrightarrow x = 0\)
Vậy x = 0
a, x= (-2). 5 :1,25 = -8
b, x= 18 : (2,4:3,6)= 18: 2/3 = 18 x 3/2 = 27
c, x+1= (0,5:0,2) x 0,4= 2,5 x 0,4= 1
=> x=1-1=0
a) (3x-2):\(1\frac{2}{5}\)=\(2\frac{3}{7}\)
(3x-2):\(\frac{7}{5}\)=\(\frac{17}{7}\)
3x-2 =\(\frac{17}{7}.\frac{7}{5}\)
3x-2 =\(\frac{17}{5}\)
3x =\(\frac{17}{5}+2\)
3x =\(\frac{27}{5}\)
x =\(\frac{27}{5}:3\)
x =\(\frac{27}{5}.\frac{1}{3}\)
x =\(\frac{9}{5}\)
b) x:0,16=9:x
x.x =9.0,16
x2 =\(\frac{36}{25}\)
x2 =\(\left(\frac{6}{5}\right)^2\)
⇒x =\(\frac{6}{5}\)
a) Ta có: \(\left(3x-2\right):1\frac{2}{5}=2\frac{3}{7}:2\frac{3}{5}\)
\(\Leftrightarrow\left(3x-2\right):\frac{7}{5}=\frac{17}{7}:\frac{13}{5}\)
\(\Leftrightarrow\left(3x-2\right)\cdot\frac{5}{7}=\frac{17}{7}\cdot\frac{5}{13}=\frac{85}{91}\)
\(\Leftrightarrow3x-2=\frac{85}{91}:\frac{5}{7}=\frac{85}{91}\cdot\frac{7}{5}=\frac{17}{13}\)
\(\Leftrightarrow3x=\frac{17}{13}+2=\frac{43}{13}\)
\(\Leftrightarrow x=\frac{43}{13}:3=\frac{43}{13}\cdot\frac{1}{3}\)
hay \(x=\frac{43}{39}\)
Vậy: \(x=\frac{43}{39}\)
b) ĐKXĐ: x≠0
Ta có: \(\frac{x}{0.16}=\frac{9}{x}\)
\(\Leftrightarrow x\cdot x=9\cdot0.16\)
\(\Leftrightarrow x^2=1.44\)
hay \(x\in\left\{1.2;-1.2\right\}\)(nhận)
Vậy: \(x\in\left\{1.2;-1.2\right\}\)
Bài 2:
a: =>x/4=1/8
hay x=1/2
b: \(\Leftrightarrow\dfrac{x}{-5}=\dfrac{11}{6}\)
hay x=-55/6
c: \(\Leftrightarrow\dfrac{-3.5}{x}=\dfrac{4.25}{8}\)
hay x=-112/17
a)\(\frac{x-1}{x+2}=\frac{x-2}{x+3}\Rightarrow\left(x-1\right)\left(x+3\right)=\left(x+2\right)\left(x-2\right)\)
\(\Rightarrow x^2+2x-3=x^2-4\)
\(\Rightarrow2x=-1\)
\(\Rightarrow x=-\frac{1}{2}\)
b)\(\frac{37-x}{x+13}=\frac{3}{7}\)\(\Rightarrow7\left(37-x\right)=3\left(x+13\right)\)
\(\Rightarrow259-7x=3x+39\)
\(\Rightarrow10x=220\)
\(\Rightarrow x=22\)
a) \(\frac{3x-2}{1\frac{2}{5}}=\frac{2\frac{3}{7}}{2\frac{3}{5}}\Rightarrow3x-2=1.\frac{2}{5}.\frac{2\frac{3}{7}}{2\frac{3}{5}}=\frac{7}{5}.\frac{17}{7}.\frac{5}{13}\)
\(3x-2=\frac{17}{13}\Rightarrow3x=2+\frac{17}{13}=\frac{43}{13}\Rightarrow x=\frac{43}{39}.\)
b) \(\frac{x}{0,16}=\frac{9}{x}\Rightarrow x^2=9.0,16=1,44\Rightarrow x=\pm1,2\)