\(\dfrac{x}{6}+\dfrac{3}{x+2}=\dfrac{2}{3}\)
tìm gt của x
Tìm x, biết
a)\(\dfrac{1}{2}\)x\(x\)-\(\dfrac{7}{3}\)=\(\dfrac{-5}{6}\)+\(\dfrac{3}{4}\)x\(x\)
b)\(\dfrac{4}{5}\)x\(x\)-\(\dfrac{6}{5}\)=\(\dfrac{1}{2}\)+\(\dfrac{3}{2}\)x\(x\)
c)\(\dfrac{2}{5}\)x(3x\(x\)+\(\dfrac{3}{4}\))=\(1\dfrac{1}{5}\)-\(\dfrac{1}{3}\)x\(x\)
d)2x(3x\(x \)+\(\dfrac{3}{4}\))+\(\dfrac{4}{5}\)=\(\dfrac{1}{2}\)-2x\(x\)
giúp mình giải bài toán trên với. Mình cảm ơn rất nhiều
a: =>1/2x-3/4x=-5/6+7/3
=>-1/4x=14/6-5/6=3/2
=>x=-3/2*4=-6
b: =>4/5x-3/2x=1/2+6/5
=>-7/10x=17/10
=>x=-17/7
c: =>6/5x+6/20=6/5-1/3x
=>6/5x+1/3x=6/5-3/10=12/10-3/10=9/10
=>x=27/46
d: =>6x+3/2+4/5=1/2-2x
=>8x=1/2-3/2-4/5=-1-4/5=-9/5
=>x=-9/40
Bài 2: Cho A = \(\dfrac{x}{x+2}\)
B = \(\dfrac{x^2}{x^2-4}-\dfrac{1}{2-x}+\dfrac{1}{x+2}\)
a. Tìm đkxđ của A,B
b. Rút gọn B
c. Tìm gt nguyên lớn nhất của x để B nguyên
d. Ta có: P = A.B. Tìm x để P = \(\dfrac{3}{2}\)
Tìm x, biết:
a) \(x:\dfrac{6}{13}=\dfrac{13}{7}\) b) \(\dfrac{4}{7}.x-\dfrac{2}{3}=\dfrac{1}{5}\) c) \(\left(\dfrac{3}{10}-x\right):\dfrac{2}{5}=\dfrac{3}{5}\) d) \(\dfrac{2}{3}.x-\dfrac{7}{6}=\dfrac{5}{2}\)
a) \(x:\dfrac{6}{13}=\dfrac{13}{7}\\ \Rightarrow x=\dfrac{13}{7}.\dfrac{6}{13}\\ \Rightarrow x=\dfrac{6}{7}\)
b) \(\dfrac{4}{7}.x-\dfrac{2}{3}=\dfrac{1}{5}\\ \Rightarrow\dfrac{4}{7}.x=\dfrac{13}{15}\\ \Rightarrow x=\dfrac{91}{60}\)
c) \(\left(\dfrac{3}{10}-x\right):\dfrac{2}{5}=\dfrac{3}{5}\\ \Rightarrow\dfrac{3}{10}-x=\dfrac{6}{25}\\ \Rightarrow x=\dfrac{3}{50}\)
d) \(\dfrac{2}{3}x-\dfrac{7}{6}=\dfrac{5}{2}\\ \Rightarrow\dfrac{2}{3}x=\dfrac{11}{3}\\ \Rightarrow x=\dfrac{11}{2}\)
\(a,\)\(x:\dfrac{6}{13}=\dfrac{13}{7}\)
\(x=\dfrac{13}{7}.\dfrac{6}{13}\)
\(x=\dfrac{6}{7}\)
b,\(\dfrac{4}{7}.x-\dfrac{2}{3}=\dfrac{1}{5}\)
\(\dfrac{4}{7}.x=\dfrac{1}{5}+\dfrac{2}{3}\)
\(\dfrac{4}{7}.x=\dfrac{3}{15}+\dfrac{10}{15}\)
\(\dfrac{4}{7}.x=\dfrac{13}{15}\)
\(x=\dfrac{13}{15}:\dfrac{4}{7}\)
\(x=\dfrac{13}{15}.\dfrac{7}{4}\)
\(x=\dfrac{91}{60}\)
a: Ta có: \(x:\dfrac{6}{13}=\dfrac{13}{7}\)
\(\Leftrightarrow x=\dfrac{13}{7}\cdot\dfrac{6}{13}\)
hay \(x=\dfrac{6}{7}\)
b: Ta có: \(\dfrac{4}{7}x-\dfrac{2}{3}=\dfrac{1}{5}\)
\(\Leftrightarrow x\cdot\dfrac{4}{7}=\dfrac{13}{15}\)
hay \(x=\dfrac{91}{60}\)
Cm
a.\(\dfrac{3}{2}\sqrt{6}+2\sqrt{\dfrac{2}{3}}-4\sqrt{\dfrac{3}{2}}=\dfrac{\sqrt{6}}{6}\)
b. \(\dfrac{\sqrt{y}}{x-\sqrt{xy}}+\dfrac{\sqrt{x}}{y-\sqrt{xy}}=-\dfrac{\sqrt{x}+\sqrt{y}}{\sqrt{xy}}\)với x>0, y>o và x≠y
a: \(=\dfrac{3}{2}\sqrt{6}+\dfrac{2}{3}\sqrt{6}-2\sqrt{6}\)
\(=\dfrac{1}{6}\sqrt{6}\)
b: \(VT=\dfrac{\sqrt{y}}{\sqrt{x}\left(\sqrt{x}-\sqrt{y}\right)}+\dfrac{\sqrt{x}}{\sqrt{y}\left(\sqrt{y}-\sqrt{x}\right)}\)
\(=\dfrac{y-x}{\sqrt{xy}\left(\sqrt{x}-\sqrt{y}\right)}=\dfrac{-\left(\sqrt{x}+\sqrt{y}\right)}{\sqrt{xy}}\)
Bài 61 (trang 33 SGK Toán 9 Tập 1)
Chứng minh các đẳng thức sau:
a) $\dfrac{3}{2} \sqrt{6}+2 \sqrt{\dfrac{2}{3}}-4 \sqrt{\dfrac{3}{2}}=\dfrac{\sqrt{6}}{6}$;
b) $\left(x \sqrt{\dfrac{6}{x}}+\sqrt{\dfrac{2 x}{3}}+\sqrt{6 x}\right): \sqrt{6 x}=2 \dfrac{1}{3} $ với $x>0$.
a) -17√3/3 b) 11√6
c) 21 d) 11
a) và làm tiếp.
và làm tiếp
a) \(\frac{3}{2}\sqrt{6}+2\sqrt{\frac{2}{3}}-4\sqrt{\frac{3}{2}}\)
\(=\frac{3}{2}\sqrt{6}+\frac{2}{3}\sqrt{6}-\frac{4}{2}\sqrt{6}\)
\(=\left(\frac{3}{2}+\frac{2}{3}-\frac{4}{2}\right)\sqrt{6}\)
\(=\frac{1}{6}\cdot\sqrt{6}=\frac{\sqrt{6}}{6}\left(đpcm\right)\)
b) \(\left(x\sqrt{\frac{6}{x}}+\sqrt{\frac{2x}{3}}+\sqrt{6x}\right):\sqrt{6x}\)
\(=\left(\sqrt{6x}+\frac{1}{3}\sqrt{6x}+\sqrt{6x}\right):\sqrt{6x}\)
\(=\left[\left(1+\frac{1}{3}+1\right)\sqrt{6x}\right]:\sqrt{6x}\)
\(=\frac{7}{3}\sqrt{6x}:\sqrt{6x}=\frac{7}{3}=2\frac{1}{3}\left(đpcm\right)\)
Bài 3 Tìm x
\(\dfrac{1}{2}:3+x=1\dfrac{2}{3}\)
\(2\dfrac{3}{4}-x=\dfrac{5}{6}+\dfrac{2}{3}\)
\(5\dfrac{4}{10}-x\) X\(\dfrac{3}{4}=\dfrac{2}{3}\)
\(\dfrac{1}{2}:3+x=1\dfrac{2}{3}\\ \Leftrightarrow x=\dfrac{5}{3}-\dfrac{1}{6}\\ \Leftrightarrow x=\dfrac{3}{2}\\2\dfrac{3}{4}-x=\dfrac{5}{6}+\dfrac{2}{3}\\ \Leftrightarrow x=\dfrac{11}{4}-\dfrac{5}{6}-\dfrac{2}{3} \\ \Leftrightarrow x=\dfrac{5}{4}\\ 5\dfrac{4}{10}-\dfrac{3}{4}\times x=\dfrac{2}{3}\\ \Leftrightarrow\dfrac{3}{4}x=\dfrac{54}{10}-\dfrac{2}{3}\\ \Leftrightarrow x=\dfrac{284}{45}\)
1) ....
1/2 : 3 = 5/3 - x
1/6 = 5/3 - x
x = 5/3 - 1/6 =3/2
2)....
11/4 - x = 3/2
x = 11/4 - 3/2 =5/4
3)...
27/5 - 3/4x = 2/3
3/4x = 27/5 - 2/3 =71/15
x = 71/15 : 3/4 =284/45
CM:
\(\dfrac{3}{2}\sqrt{6}+2\sqrt{\dfrac{2}{3}}-4\sqrt{\dfrac{3}{4}}=\dfrac{\sqrt{6}}{6}\)
\(\dfrac{x\sqrt{y}+y\sqrt{x}}{\sqrt{xy}}:\dfrac{1}{\sqrt{x}+\sqrt{y}}=x-y\) với x.0, y>0, x≠y
\(\dfrac{\sqrt{y}}{x-\sqrt{xy}}+\dfrac{\sqrt{x}}{y-\sqrt{xy}}=\dfrac{\sqrt{x}+\sqrt{y}}{\sqrt{xy}}\)với x>0, y>0, x≠y
a: \(=\dfrac{3}{2}\sqrt{6}+\dfrac{2}{3}\sqrt{6}-2\sqrt{3}=\dfrac{13}{6}\sqrt{6}-2\sqrt{3}\)
b: \(VT=\dfrac{\sqrt{xy}\left(\sqrt{x}+\sqrt{y}\right)}{\sqrt{xy}}\cdot\left(\sqrt{x}+\sqrt{y}\right)=\left(\sqrt{x}+\sqrt{y}\right)^2\)
c: \(VT=\dfrac{\sqrt{y}}{\sqrt{x}\left(\sqrt{x}-\sqrt{y}\right)}+\dfrac{\sqrt{x}}{\sqrt{y}\left(\sqrt{y}-\sqrt{x}\right)}\)
\(=\dfrac{y-x}{\sqrt{xy}\left(\sqrt{x}-\sqrt{y}\right)}=\dfrac{-\left(\sqrt{x}+\sqrt{y}\right)}{\sqrt{xy}}\)
1)\(\dfrac{2x-1}{6}\)\(-\dfrac{3x+2}{9}\)\(<0\)
2)3x>-6
3)\(\dfrac{1}2x<4\)
4) -8x>24
5) 3x-1<8
6)\(\dfrac{x+6}{5}-\dfrac{x-2}{3}<2\)
7) \(\dfrac{x-2}{10}+\dfrac{x-5}{15}>\dfrac{10x-1}{30}\)
8) \(X-\dfrac{x-1}{3}+\dfrac{x+2}{6}>\dfrac{2x}{5}+5\)
2) 3x > -6
⇔ x > \(-\frac{6}{3}\)
\(\Leftrightarrow x>-2\)
1.Cho B=\(\left(\dfrac{x-2}{x^2-5x+6}-\dfrac{x+3}{2-x}-\dfrac{x+2}{x-3}\right):\left(2-\dfrac{x}{x+1}\right)\)
a) Tìm đkxđ của B
b) Rút gọn B
c) Tìm x để B = 0
2. Cho C = \(\left(\dfrac{1}{x-1}-\dfrac{2x}{x^3-x^2+x-1}\right):\left(\dfrac{x^2+x}{x^3+x^2+x+1}+\dfrac{1}{x+1}\right)\)
a) Tìm đkxđ của C
b) Rút gọn C
c) Tìm x để C = \(\dfrac{2}{5}\)
d) Tìm x thuộc Z để giá trị C là số nguyên
Bài 4. Tìm x biết:
a. \(\dfrac{x}{5}=\dfrac{2}{5},\dfrac{3}{8}=\dfrac{6}{x},\dfrac{1}{9}=\dfrac{x}{27}\)
b. \(\dfrac{4}{x}=\dfrac{8}{6},\dfrac{3}{x-5}=\dfrac{-4}{x+2},\dfrac{x}{-2}=\dfrac{-8}{x}\)
a,2/5 = 2/5 ; 3/8=6/16 ; 1/9=3/27
b, 4/3=8/6 ; -1=-1 ; -4/-2=-8/4
tick cho mik nhé
a) x= 2, x= 8.(6 : 3) = 16, x= 1. (27 : 9)= 3
b) x= 6 : (8 : 4) = 3, x= -1, x= -2 . -8 = x.x => 16 = x2 => 42 = x2 => x=4
Tick cho mình đi