a) x + 1/4 = 5/8
b) x - 1/3 = 1/6
c) x : 1/6 = 9/10
Tìm x :
a. x+ 6 và 1/8 =8
b. 11/2 * x = 1/5 :1/3
c. x*3/5 + 2/5 *x =4/9 + 1/3
Chú thích : dấu * là dấu nhân
a: \(x+6\dfrac{1}{8}=8\)
=>\(x+\dfrac{49}{8}=\dfrac{64}{8}\)
=>\(x=\dfrac{64}{8}-\dfrac{49}{8}=\dfrac{15}{8}\)
b: \(\dfrac{11}{2}\cdot x=\dfrac{1}{5}:\dfrac{1}{3}\)
=>\(x\cdot\dfrac{11}{2}=\dfrac{1}{5}\cdot3=\dfrac{3}{5}\)
=>\(x=\dfrac{3}{5}:\dfrac{11}{2}=\dfrac{3}{5}\cdot\dfrac{2}{11}=\dfrac{6}{55}\)
c: \(x\cdot\dfrac{3}{5}+\dfrac{2}{5}\cdot x=\dfrac{4}{9}+\dfrac{1}{3}\)
=>\(x\left(\dfrac{3}{5}+\dfrac{2}{5}\right)=\dfrac{4}{9}+\dfrac{3}{9}\)
=>\(x\cdot1=\dfrac{7}{9}\)
=>\(x=\dfrac{7}{9}\)
a, 4*(3-x)^10=9(3-x)^8
b, (x-1)^x+3=(x-1)^x+1
`4.(3-x)^10=9(3-x)^8`
`=>(3-x)^{8}(4(3-x)^2-9)=0`
`=>` $\left[ \begin{array}{l}3-x=0\\(3-x)^2=\dfrac{9}{4}\end{array} \right.$
`=>` $\left[ \begin{array}{l}x=3\\3-x=\dfrac{3}{2}\\3-x=-\dfrac{3}{2}\end{array} \right.$
`=>` $\left[ \begin{array}{l}x=3\\x=\dfrac{3}{2}\\x=\dfrac{9}{2}\end{array} \right.$
Vậy `x=3` hoặc `x=3/2` hoặc `x=9/2`
`b,(x-1)^{x+3}=(x-1)^{x+1}`
`=>(x-1)^{x+1}[(x-1)^2-1]=0`
`=>` $\left[ \begin{array}{l}x-=1\\x-=-1\end{array} \right.$
`=>` $\left[ \begin{array}{l}x=2\\x=1\\x=0\end{array} \right.$
Vậy `x=0` hoặc `x=1` hoặc `x=2`
a) 4(3 - x)10 = 9(3 - x)8
=> (x - 3)8.[4(x - 3)2 - 9) = 0
<=> (x - 3)8.(2x - 6 - 3)(2x - 6 + 3) = 0
<=> (x - 3)8(2x - 9)(2x - 3) = 0
<=> \(\left[{}\begin{matrix}x-3=0\\2x-9=0\\2x-3=0\end{matrix}\right.\)
<=> \(\left[{}\begin{matrix}x=3\\x=\dfrac{9}{2}\\x=\dfrac{3}{2}\end{matrix}\right.\)
Vậy S = {3;9/2; 3/2}
b) (x - 1)x + 3 = (x - 1)x + 1
<=> (x - 1)x + 1.[(x - 3)2 - 1) = 0
<=>(x - 1)x + 1.(x - 3 - 1)(x - 3 + 1) = 0
<=> (x - 1)x + 1.(x - 4)(x - 2) = 0
<=> \(\left[{}\begin{matrix}x-1=0\\x-4=0\\x-2=0\end{matrix}\right.\)
<=> \(\left[{}\begin{matrix}x=1\\x=4\\x=2\end{matrix}\right.\)
b) Ta có: \(\left(x-1\right)^{x+3}=\left(x-1\right)^{x+1}\)
\(\Leftrightarrow\left(x-1\right)^{x+3}-\left(x-1\right)^{x+1}=0\)
\(\Leftrightarrow\left(x-1\right)^{x+1}\left[\left(x-1\right)^2-1\right]=0\)
\(\Leftrightarrow\left[{}\begin{matrix}\left(x-1\right)^{x+1}=0\\\left(x-1\right)^2-1=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x-1=0\\\left(x-1\right)^2=1\end{matrix}\right.\)
\(\Leftrightarrow\left[{}\begin{matrix}x-1=0\\x-1=1\\x-1=-1\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=1\\x=2\\x=0\end{matrix}\right.\)
Vậy: S={0;1;2}
a) X + 1/4 = 5/8
b) X - 3/5 = 1/10
c) X x 2/7 = 6/11
d) X : 3/2 = 1/4
đ) 7/4 - X = 5/7
e) 5/4 : x = 1/8
\(a,x+\dfrac{1}{4}=\dfrac{5}{8}\)
\(\Leftrightarrow x=\dfrac{5}{8}-\dfrac{1}{4}\)
\(\Leftrightarrow x=\dfrac{5}{8}-\dfrac{2}{8}\)
\(\Leftrightarrow x=\dfrac{3}{8}\)
\(b,x-\dfrac{3}{5}=\dfrac{1}{10}\)
\(\Leftrightarrow x=\dfrac{1}{10}+\dfrac{3}{5}\)
\(\Leftrightarrow x=\dfrac{1}{10}+\dfrac{6}{10}\)
\(\Leftrightarrow x=\dfrac{7}{10}\)
\(c,x\times\dfrac{2}{7}=\dfrac{6}{11}\)
\(\Leftrightarrow x=\dfrac{6}{11}:\dfrac{2}{7}\)
\(\Leftrightarrow x=\dfrac{6}{11}\times\dfrac{7}{2}\)
\(\Leftrightarrow x=\dfrac{42}{22}\)
\(\Leftrightarrow x=\dfrac{21}{11}\)
\(d,x:\dfrac{3}{2}=\dfrac{1}{4}\)
\(\Leftrightarrow x=\dfrac{1}{4}\times\dfrac{3}{2}\)
\(\Leftrightarrow x=\dfrac{3}{8}\)
\(đ,\dfrac{7}{4}-x=\dfrac{5}{7}\)
\(\Leftrightarrow x=\dfrac{7}{4}-\dfrac{5}{7}\)
\(\Leftrightarrow x=\dfrac{49}{28}-\dfrac{20}{28}\)
\(\Leftrightarrow x=\dfrac{29}{28}\)
\(e,\dfrac{5}{4}:x=\dfrac{1}{8}\)
\(x=\dfrac{5}{4}:\dfrac{1}{8}\)
\(\Leftrightarrow x=\dfrac{5}{4}\times8\)
\(\Leftrightarrow x=\dfrac{40}{4}\)
\(\Leftrightarrow x=10\)
a)x/3-4/y=1/5
b)4/x+y/3=5/6
c)5/x-y/3=1/6
d)x/6-2/y=1/30
Giải pt:
a) | 5x | = 3x + 8
b) | -4x | = -2x + 11
c) | 3x - 1 | = 4x + 1
d) | 3 - 2x | = 3x - 7
e) 9 - | -5x | + 2x = 0
f) ( x + 1)² + | x + 10 | - x² - 12 = 0
g) | 4 - x | + x² - (5 + x)x = 0
h) | x - 1 | = | 2x - 3|
i) | x| + | x + 2 | = 4
k) | 2x + 1 | - | 5x - 2 | = 3
l) 2 | x | - | x + 3 | - 1 = 0
a.
\(\left|5x\right|=3x+8\Leftrightarrow\left[{}\begin{matrix}-5x=3x+8\\5x=3x+8\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=-1\\x=4\end{matrix}\right.\)
b.
\(\left|-4x\right|=-2x+11\Leftrightarrow\left[{}\begin{matrix}-4x=-2x+11\\4x=-2x+11\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{11}{2}\\x=\dfrac{11}{6}\end{matrix}\right.\)
c.
\(\left|3x-1\right|=4x+1\Leftrightarrow\left[{}\begin{matrix}-3x+1=4x+1\\3x-1=4x+1\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=0\\x=-2\end{matrix}\right.\)
d.
\(\left|3-2x\right|=3x-7\Leftrightarrow\left[{}\begin{matrix}-3+2x=3x-7\\3-2x=3x-7\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=4\\x=2\end{matrix}\right.\)
e.
\(9-\left|-5x\right|+2x=0\Leftrightarrow\left[{}\begin{matrix}9-5x+2x=0\\9+5x+2x=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=3\\x=-\dfrac{9}{7}\end{matrix}\right.\)
f.
\(\left(x+1\right)^2+\left|x+10\right|-x^2-12=0\Leftrightarrow\left[{}\begin{matrix}x^2+2x+1-x-10-x^2-12=0\\x^2+2x+1+x+10-x^2-12=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=21\\x=\dfrac{1}{3}\end{matrix}\right.\)
1.giải các phương trình sau:
a, 3(2x+1)/4 - 5x+3/6 = 2x-1/3 - 3-x/4
b, 19/4 - 2(3x-5)/5 = 3-2x/10 - 3x-1/4
c, x-2*3/2+3 + x-3*5/3+5 + x-5*2/5+2 = 10
d, x-3/5*7 + x-5/3*7 + x-7/3*5 = 2(1/3 + 1/5 + 1/7)
2. giải các phương trình:
a, x-1/9 + x-2/8 = x-3/7 + x-4/6
b, (1/1*2 + 1/2*3 + 1/3*4 + ... + 1/9*10) (x-1) + 1/10x = x- 9/10
Câu 1 :
a, \(\frac{3\left(2x+1\right)}{4}-\frac{5x+3}{6}=\frac{2x-1}{3}-\frac{3-x}{4}\)
\(\Leftrightarrow\frac{6x+3}{4}+\frac{3-x}{4}=\frac{2x-1}{3}+\frac{5x+3}{6}\)
\(\Leftrightarrow\frac{5x+6}{4}=\frac{9x+1}{6}\Leftrightarrow\frac{30x+36}{24}=\frac{36x+4}{24}\)
Khử mẫu : \(30x+36=36x+4\Leftrightarrow-6x=-32\Leftrightarrow x=\frac{32}{6}=\frac{16}{3}\)
tương tự
\(\frac{19}{4}-\frac{2\left(3x-5\right)}{5}=\frac{3-2x}{10}-\frac{3x-1}{4}\)
\(< =>\frac{19.5}{20}-\frac{8\left(3x-5\right)}{20}=\frac{2\left(3-2x\right)}{20}-\frac{5\left(3x-1\right)}{20}\)
\(< =>95-24x+40=6-4x-15x+5\)
\(< =>-24x+135=-19x+11\)
\(< =>5x=135-11=124\)
\(< =>x=\frac{124}{5}\)
\(\frac{\left(x-2\right).3}{2}+3+\frac{\left(x-3\right).5}{3}+5+\frac{\left(x-5\right).2}{5}+2=10\)
\(< =>\frac{\left(x-2\right).3.15}{30}+\frac{\left(x-3\right).5.10}{30}+\frac{\left(x-5\right).2.6}{30}=10-2-3-5\)
\(< =>\frac{\left(x-2\right).45+\left(x-3\right).50+\left(x-5\right).12}{30}=0\)
\(< =>45x-90+50x-150+12x-60=0\)
\(< =>107x-300=0< =>x=\frac{300}{107}\)
1/ x + 1/2 = -5/3 6/ x - 1/5 = 9/10
2/ 1/3 - x = 3/5 7/ x + 5/12 = 3/8
3/ 3-4 + x = 7/2 8/ x + 5/4 = 7/6
4/ x - 4/3 = -7/9 9/ x - 2/7 = 1/35
5/ x - -7/3 = 5/6 10/ x - 1/5 = -7/10
\(1,\\ x+\dfrac{1}{2}=-\dfrac{5}{3}\\ x=-\dfrac{5}{3}-\dfrac{1}{2}\\ x=-\dfrac{13}{6}\\ Vậyx=-\dfrac{13}{6}\)
\(2,\\ \dfrac{1}{3}-x=\dfrac{3}{5}\\ x=\dfrac{1}{3}-\dfrac{3}{5}\\ x=-\dfrac{4}{15}\\ Vậyx=-\dfrac{4}{15}\)
\(3,\\ 3-4+x=\dfrac{7}{2}\\ -1+x=\dfrac{7}{2}\\ x=\dfrac{7}{2}+1\\ x=\dfrac{9}{2}\\ Vậyx=\dfrac{9}{2}\)
\(4,\\ x-\dfrac{4}{3}=-\dfrac{7}{9}\\ x=-\dfrac{7}{9}+\dfrac{4}{3}\\ x=\dfrac{15}{27}\\ Vậyx=\dfrac{15}{27}\)
\(5,\\ x-\left(-\dfrac{7}{3}\right)=\dfrac{5}{6}\\ x=\dfrac{5}{6}-\dfrac{7}{3}\\ x=-\dfrac{27}{18}\\ Vậyx=-\dfrac{27}{18}\)
\(6,\\ x-\dfrac{1}{5}=\dfrac{9}{10}\\ x=\dfrac{9}{10}+\dfrac{1}{5}\\ x=\dfrac{11}{10}\\ Vậyx=\dfrac{11}{10}\)
\(7,\\ x+\dfrac{5}{12}=\dfrac{3}{8}\\ x=\dfrac{3}{8}-\dfrac{5}{12}\\ x=-\dfrac{1}{24}\\ Vậyx=-\dfrac{1}{24}\)
\(8,\\ x+\dfrac{5}{4}=\dfrac{7}{6}\\ x=\dfrac{7}{6}-\dfrac{5}{4}\\ x=-\dfrac{9}{24}\\ Vậyx=-\dfrac{9}{24}\)
\(9,\\ x-\dfrac{2}{7}=\dfrac{1}{35}\\ x=\dfrac{1}{35}+\dfrac{2}{7}\\ x=\dfrac{11}{35}\\ Vậyx=\dfrac{11}{35}\\ 10,\\ x-\dfrac{1}{5}=-\dfrac{7}{10}\\ x=-\dfrac{7}{10}+\dfrac{1}{5}\\ x=-\dfrac{1}{2}\\ Vậyx=-\dfrac{1}{2}\)
ahiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii hãy ấn a
A= ( 6 : 3/5 - 1 1/6 x 6/7 ) : ( 4 1/5 x 10/11 + 5 2/11 )
B= ( 1 - 1/2 ) x ( 1- 1/4 ) x ... x ( 1 - 1/2003 ) x ( 1 - 1/2004 )
C= 5 9/10 : 3/2 - ( 2 1/3 x 4 1/2 - 2 x 2 1/3 ) : 7/4
Giúp mình nhanh nha! Mình sẽ thick người đó
a) x/8 = 3/4 + -5/8
b) x/12 = 3/4 + -2/3
c) 1 + 11/13 = 24/x
d) x/6 - 3/4 = 1/12
`x/8 = 3/4 +(-5/8)`
`=>x/8 = 6/8 +(-5/8)`
`=>x/8 = 1/8`
`=>x=1`
`-----`
`x/12 =3/4 +(-2/3)`
`=>x/12 = 9/12 + (-8/12)`
`=> x/12=1/12`
`=>x=1`
`----`
`1+11/13=24/x`
`=> 13/13 +11/13=24/x`
`=> 24/13 =24/x`
`=>x=13`
`----`
`x/6 -3/4=1/12`
`=>x/6 = 1/12 +3/4`
`=>x/6 = 1/12 + 9/12`
`=>x/6 = 10/12`
`=>x/6= 5/6`
`=>x=5`
\(a)\)
\(\dfrac{x}{8}=\dfrac{3}{4}+\dfrac{-5}{8}\)
\(\Rightarrow\dfrac{x}{8}=\dfrac{1}{8}\)
\(\Rightarrow x.8=1.8\)
\(\Rightarrow x.8=8\)
\(\Rightarrow x=8:8\)
\(\Rightarrow x=1\)
\(b)\)
\(\dfrac{x}{12}=\dfrac{3}{4}+\dfrac{-2}{3}\)
\(\Rightarrow\dfrac{x}{12}=\dfrac{1}{12}\)
\(\Rightarrow x.12=1.12\)
\(\Rightarrow x.12=12\)
\(\Rightarrow x=12:12\)
\(\Rightarrow x=1\)
\(c)\)
\(1+\dfrac{11}{13}=\dfrac{24}{x}\)
\(\Rightarrow\dfrac{24}{13}=\dfrac{24}{x}\)
\(\Rightarrow x.24=24.13\)
\(\Rightarrow x.24=312\)
\(\Rightarrow x=312:24\)
\(\Rightarrow x=13\)
\(d)\)
\(\dfrac{x}{6}-\dfrac{3}{4}=\dfrac{1}{12}\)
\(\Rightarrow\dfrac{x}{6}=\dfrac{1}{12}+\dfrac{3}{4}\)
\(\Rightarrow\dfrac{x}{6}=\dfrac{5}{6}\)
\(\Rightarrow x.6=5.6\)
\(\Rightarrow x.6=30\)
\(\Rightarrow x=30:6\)
\(\Rightarrow x=5\)
a) 1/3x - 1/4x = 1
b) 4/5 + 5/7: x = 1/6
c) 2x/3 - x/4 = 5/6. cảm ơn :D
`a)1/3x-1/4x=1`
`(1/3-1/4)x=1`
`1/12x=1`
`x=1:1/12=12`
______________________________
`b)4/5+5/7:x=1/6`
`5/7:x=1/6-4/5`
`5/7:x=-19/30`
`x=5/7:(-19/30)`
`x=-150/133`
__________________________________
`c)[2x]/3-x/4=5/6`
`x(2/3-1/4)=5/6`
`x. 5/12=5/6`
`x=5/6:5/12=2`
a) 1/3x - 1/4x = 1
1/12x = 1
x = 1 . 12
x = 12
b) 4/5 + 5/7: x = 1/6
5/7 : x = 1/6 - 4/5
5/7 : x = -19/30
x = 5/7 : -19/30
x = -150/133
c) 2x/3 - x/4 = 5/6
4 . 2x - 3x = 10
8x - 3x = 10
5x = 10
x = 10 : 5
x = 2.