Tìm x:
a) ( 2.x -3) - ( x-5) = ( x + 2) - (x -1)
b) 2.( x-1) - 5.( x+2) = -10
Tìm x:
a, (x - 1/2) : 1/3 + 5/7 = 9 5/7
b, x + 30% x = - 1,31
c, -2/3.x + 1/5 = 1/10
\(a,\left(x-\dfrac{1}{2}\right):\dfrac{1}{3}+\dfrac{5}{7}=9\dfrac{5}{7}\)
\(\Leftrightarrow\left(x-\dfrac{1}{2}\right).3=\dfrac{68}{7}-\dfrac{5}{7}\)
\(\Leftrightarrow\left(x-\dfrac{1}{2}\right).3=9\)
\(\Leftrightarrow x-\dfrac{1}{3}=3\)
\(\Leftrightarrow x=3+\dfrac{1}{3}\)
\(\Leftrightarrow x=\dfrac{9}{3}+\dfrac{1}{3}\)
\(\Leftrightarrow x=\dfrac{10}{3}\)
\(b,x+30\%x=-1,31\)
\(\Leftrightarrow x+\dfrac{3}{10}.x=-\dfrac{131}{100}\)
\(\Leftrightarrow x.\left(1+\dfrac{3}{10}\right)=-\dfrac{131}{100}\)
\(\Leftrightarrow x.\dfrac{13}{10}=-\dfrac{131}{100}\)
\(\Leftrightarrow x=-\dfrac{131}{100}.\dfrac{10}{13}\)
\(\Leftrightarrow x=-\dfrac{131}{130}\)
\(c,-\dfrac{2}{3}x+\dfrac{1}{5}=\dfrac{1}{10}\)
\(\Leftrightarrow\dfrac{-2}{3}x=\dfrac{1}{10}-\dfrac{1}{5}\)
\(\Leftrightarrow\dfrac{-2}{3}x=\dfrac{1}{10}-\dfrac{2}{10}\)
\(\Leftrightarrow-\dfrac{2}{3}x=-\dfrac{1}{10}\)
\(\Leftrightarrow x=-\dfrac{1}{10}.\left(-\dfrac{3}{2}\right)\)
\(\Leftrightarrow x=\dfrac{3}{20}\)
Tìm x:
a. 1/3+x=5/6
b.|x-1|-2/5=11/10 c.1/3+2/3(x/2+3)=1
d.x+2/3 = 27/x+2
a.\(\dfrac{1}{3}\) + x = \(\dfrac{5}{6}\)
x = \(\dfrac{5}{6}\) - \(\dfrac{1}{3}\)
x = \(\dfrac{1}{2}\)
b. | x-1| - \(\dfrac{2}{5}\) = \(\dfrac{11}{10}\)
| x-1| = \(\dfrac{11}{10}\) + \(\dfrac{2}{5}\)
|x-1| = \(\dfrac{3}{2}\)
\(\left[{}\begin{matrix}x-1=\dfrac{3}{2}\\x-1=-\dfrac{3}{2}\end{matrix}\right.\)
\(\left[{}\begin{matrix}x=\dfrac{3}{2}+1\\x=-\dfrac{3}{2}+1\end{matrix}\right.\)
\(\left[{}\begin{matrix}x=\dfrac{5}{2}\\x=-\dfrac{1}{2}\end{matrix}\right.\)
c, \(\dfrac{1}{3}\) + \(\dfrac{2}{3}\) ( \(\dfrac{x}{2}\) + 3) = 1
\(\dfrac{2}{3}\) (\(\dfrac{x}{2}\) + 3) = 1 - \(\dfrac{1}{3}\)
\(\dfrac{2}{3}\) ( \(\dfrac{x}{2}\) + 3) = \(\dfrac{2}{3}\)
\(\dfrac{x}{2}\) + 3 = 1
\(\dfrac{x}{2}\) = 1 - 3
\(\dfrac{x}{2}\) = -2
\(x\) = -4
d, \(\dfrac{x+2}{3}\) = \(\dfrac{27}{x+2}\)
(x+2)2 = 27.3
(x+2) =92
\(\left[{}\begin{matrix}x+2=9\\x+2=-9\end{matrix}\right.\)
\(\left[{}\begin{matrix}x=7\\x=-11\end{matrix}\right.\)
Tìm x:
a) x - 1\(\dfrac{3}{5}\)= 2\(\dfrac{1}{10}\) b) \(5\dfrac{1}{7}\) : x = \(4\dfrac{1}{2}\)
\(a,x-1\dfrac{3}{5}=2\dfrac{1}{10}\\ x-\dfrac{8}{5}=\dfrac{21}{10}\\ x=\dfrac{21}{10}+\dfrac{8}{5}\\ x=\dfrac{21}{10}+\dfrac{16}{10}\\ x=\dfrac{37}{10}\\ b,5\dfrac{1}{7}:x=4\dfrac{1}{2}\\ \dfrac{36}{7}:x=\dfrac{9}{2}\\ x=\dfrac{36}{7}:\dfrac{9}{2}\\ x=\dfrac{36}{7}\cdot\dfrac{2}{9}\\ x=\dfrac{8}{7}\)
Tìm x:
a) \(x-\dfrac{2}{3}=\dfrac{3}{5}-\dfrac{1}{4}\)
b) \(-\dfrac{2}{3}.x+\dfrac{1}{5}=\dfrac{1}{10}\)
x - 2/3 = 3/5 - 1/4
x - 2/3 = 7/20
x = 7/20 + 2/3
x = 61/60
- 2/3 . x + 1/5 = 1/10
-2/3 . x = 1/10 - 1/5
- 2/3 . x = -1/10
x = -1/10 : -2/3
x = 3/20
tìm x:
a, (2x - 3) - (x - 5) = (x + 2) - (x - 1)
b, 2(x - 1) - 5 (x + 2) = -10
mong các bạn giúp mình :333
Arigato :333
a) Ta có: \(\left(2x-3\right)-\left(x-5\right)=\left(x+2\right)-\left(x-1\right)\)
\(\Leftrightarrow2x-3-x+5=x+2-x+1\)
\(\Leftrightarrow x+2=3\)
hay x=1
Vậy: x=1
b) Ta có: \(2\left(x-1\right)-5\left(x+2\right)=-10\)
\(\Leftrightarrow2x-2-5x-10=-10\)
\(\Leftrightarrow-3x=-10+10+2=2\)
hay \(x=-\dfrac{2}{3}\)
Vậy: \(x=-\dfrac{2}{3}\)
a, (2x - 3) - (x - 5) = (x + 2) - (x - 1)
2x - 3 - x + 5 = x + 2 - x + 1
(2x - x) + (-3 + 5) = (x - x) + (2 + 1)
x + 2 = 3
x = 1
2. Tìm x:
a) 4/5 + x = 2/3
b) 1/2 - x = 7/12
c) 3 và 1/2 : x = -7/2
d) 3/8 - 1/6 x =5/2
e) x + 50%x = -1,5
a: x=2/3-4/5=10/15-12/15=-2/15
b: 1/2-x=7/12
=>x=1/2-7/12=-1/12
c: =>7/2:x=-7/2
=>x=-1
d: =>1/6x=3/8-5/2=3/8-20/8=-17/8
=>x=-17/8*6=-102/8=-51/4
e: =>1,5x=-1,5
=>x=-1
bài 1 tìm x:a)(x+2)^3-(x+5)(x^2+x-3)
b)(x+1)^2=2(x+1)(x+2)+(x+2)^2=9
c)(x+2)^3-(x+5)(x^2+x-3)=5
d)(12x-5)(4x-1)+(3x-7)(1-16x)=81
Tìm x:
a) (x - 5)(x + 3) = x(x - 3)
b) (x + 2)2 = (x - 1)(x + 2)
c) (x - 6)(x + 6) = x2
d) (2x - 3)2 = 4x2 - 8
a: Ta có: \(\left(x-5\right)\left(x+3\right)=x\left(x-3\right)\)
\(\Leftrightarrow x^2-2x-15-x^2+3x=0\)
\(\Leftrightarrow x=15\)
b: Ta có: \(\left(x+2\right)^2=\left(x-1\right)\left(x+2\right)\)
\(\Leftrightarrow x+2=0\)
hay x=-2
c: Ta có: \(\left(x-6\right)\left(x+6\right)=x^2\)
\(\Leftrightarrow x^2-36=x^2\)(vô lý)
a. (x - 5)(x + 3) = x(x - 3)
<=> x2 + 3x - 5x - 15 = x2 - 3x
<=> x2 - x2 + 3x - 5x + 3x - 15 = 0
<=> x = 15
b. (x + 2)2 = (x - 1)(x + 2)
<=> x2 + 4x + 4 = x2 + 2x - x - 2
<=> x2 - x2 + 4x - 2x + x = -2 - 4
<=> 3x = -5
<=> \(x=\dfrac{-5}{3}\)
c. (x - 6)(x + 6) = x2
<=> x2 - 36 - x2 = 0
<=> x2 - x2 = 36
<=> 0 = 36 (vô lí)
Vậy nghiệm của PT là \(S=\varnothing\)
d. (2x - 3)2 = 4x2 - 8
<=> 4x2 - 12x + 9 - 4x2 + 8 = 0
<=> 4x2 - 4x2 - 12x = -8 - 9
<=> -12x = -17
<=> \(x=\dfrac{17}{12}\)
Tìm x:
a) x - \(\dfrac{5}{7}\) = \(\dfrac{3}{5}\) x \(\dfrac{1}{2}\) b) x \(x\dfrac{2}{3}=\dfrac{5}{8}+\dfrac{3}{4}\)
\(a,x-\dfrac{5}{7}=\dfrac{3}{5}\times\dfrac{1}{2}\)
\(x-\dfrac{5}{7}=\dfrac{3}{10}\)
\(x=\dfrac{3}{10}+\dfrac{5}{7}\)
\(x=\dfrac{21}{70}+\dfrac{50}{70}\)
\(x=\dfrac{71}{70}\)
\(Vayx=\dfrac{71}{70}\)
\(b,x\times\dfrac{2}{3}=\dfrac{5}{8}+\dfrac{3}{4}\)
\(x\times\dfrac{2}{3}=\dfrac{5}{8}+\dfrac{6}{8}\)
\(x\times\dfrac{2}{3}=\dfrac{11}{8}\)
\(x=\dfrac{11}{8}:\dfrac{2}{3}\)
\(x=\dfrac{11}{8}\times\dfrac{3}{2}\)
\(x=\dfrac{33}{16}\)
\(Vayx=\dfrac{33}{16}\)
1 . Tìm x:
a) x.2 / -15 = -5/3
b) x-1 / -12 = -3 / x - 1
a) \(\dfrac{x.2}{-15}=\dfrac{-5}{3}\)
\(\dfrac{x.2}{-15}=\dfrac{25}{-15}\)
x.2=25
x=12,5
b) \(\dfrac{x-1}{-12}=\dfrac{-3}{x-1}\)
(x-1)2=-3.(-12)
(x-1)2=36
⇒(x-1)2\(\Rightarrow\left[{}\begin{matrix}x-1=6\\x-1=-6\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=7\\x=-5\end{matrix}\right.\)