Tìm x,biết
C=\(\frac{2x^2-3x-9}{x^2-9}=0\)
Tìm x:
a, x(2x – 3) – 2(3 – 2x) = 0
b, (x – 3)(x2 + 3x + 9) – x(x + 2)(x – 2) = 1
c, 4x2 + 4x – 6 = 2
d, 2x2 + 7x + 3 = 0
\(a,\Leftrightarrow\left(2x-3\right)\left(x+2\right)=0\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{3}{2}\\x=-2\end{matrix}\right.\\ b,\Leftrightarrow x^3-27-x^3+4x=1\\ \Leftrightarrow4x=28\Leftrightarrow x=7\\ c,\Leftrightarrow4x^2-4x-8=0\\ \Leftrightarrow x^2-x-2=0\\ \Leftrightarrow\left(x-2\right)\left(x+1\right)=0\Leftrightarrow\left[{}\begin{matrix}x=2\\x=-1\end{matrix}\right.\\ d,\Leftrightarrow2x^2+6x+x+3=0\\ \Leftrightarrow\left(x+3\right)\left(2x+1\right)=0\Leftrightarrow\left[{}\begin{matrix}x=-3\\x=-\dfrac{1}{2}\end{matrix}\right.\)
tìm x , y thuộc Z biết :
a, 4.(x +1 ) - (3x-1) = 14
b, (x^2 - 9 ). (x +2 )=0
c,(x^2 + 9 ) . (2x - 4) = 0
d, xy + 2x - y = 2
tìm x , y thuộc Z biết ;
a, 4 .( x+1) - (3x - 1) = 14
b, (x^2 - 9 ). (x+ 2) =0
c, (x^2 +9) . (2x -4) =0
d, xy +2x -y =2
a)4x+4-3x+1=14
x+5=14
x=11
b)trường hợp 1 x2-9=0
x2=9
->x=3;-3
-trường hợp 2: x+2=0
x=-2
c)-th1:x2+9=0
x2=-9
->x rỗng
d)xy+2x-y-2=0
(xy-y)+(2x-2)=0
y(x-1)+2(x-1)=0
(y+2)(x-1)=0
th1: y+2=0
y=-2
th2:x-1=0
x=1
(th1: trường hợp 1)
Tìm x biết: \(\frac{x-1}{3}+\frac{3x-5}{2}+\frac{2x}{9}+\frac{-5x+3}{9}=\frac{210}{420}\)
=>\(\frac{6\left(x-1\right)}{18}+\frac{9\left(3x-5\right)}{18}+\frac{2\left(2x\right)}{18}+\frac{2\left(-5x+3\right)}{18}=\frac{1}{2}\)
=>\(\frac{6x-6}{18}+\frac{27x-45}{18}+\frac{4x}{18}+\frac{-10x+6}{18}=\frac{1}{2}\)
=>\(\frac{\left(6x-6\right)+\left(27x-45\right)+4x+\left(-10x+6\right)}{18}=\frac{1}{2}\)
=>\(\frac{27x-45}{18}=\frac{1}{2}\)
=>54x-90=18
54x =108
=>x=2
cho A=\(\left(\frac{2}{x^2-3x}-\frac{1}{x-3}\right)\cdot\frac{x^2-6x+9}{x-2}\)
a,Rút gọn A
b,tìm x để A>0
c,khi x>0,x khác 3 hãy tìm MinP=A+3x
TÌM X
(2x-3)^2-4x-9=0
(3x-7).(3x+7)-54x-9x^2=0
(x+8)^2-x^2= 24
(x-2).(x^2+2x+4)+8-4x= 0
Em cảm ơn ạ
Tìm x, biết:
a, \(\frac{1}{4}\)+ \(\frac{1}{3}\): 2x = -5
b, ( 3x - \(\frac{1}{4}\)) . ( x + \(\frac{1}{2}\)) = 0
c, ( 2x - 5 ) . ( \(\frac{3}{2}\)x + 9 ) . ( 0,3x - 12 ) = 0
\(\frac{1}{4}+\frac{1}{3}:2x=-5\)
\(\frac{1}{3}:2x=-5-\frac{1}{4}\)
\(\frac{1}{3}:2x=\frac{-21}{4}\)
\(2x=\frac{1}{3}:\frac{-21}{4}\)
\(2x=\frac{-4}{63}\)
\(x=\frac{-4}{63}:2\)
\(x=\frac{-2}{63}\)
\(\)
\(\frac{1}{4}+\frac{1}{3}:2x=-5\)
\(\Rightarrow\frac{1}{3}:2x=-\frac{21}{4}\)
\(\Rightarrow2x=\frac{-4}{63}\)
\(\Rightarrow x=\frac{-2}{63}\)
\(\left(3x-\frac{1}{4}\right)\left(x+\frac{1}{2}\right)=0\)
\(\Rightarrow\orbr{\begin{cases}3x-\frac{1}{4}=0\\x+\frac{1}{2}=0\end{cases}\Rightarrow\orbr{\begin{cases}x=\frac{1}{12}\\x=\frac{-1}{2}\end{cases}}}\)
\(\left(2x-5\right)\left(\frac{3}{2}x+9\right)\left(0,3x-12\right)=0\)
Th1 : \(2x-5=0\Rightarrow x=\frac{5}{2}\)
Th2 : \(\frac{3}{2}x+9=0\Rightarrow x=-6\)
Th3 : \(0,3x-12=0\Rightarrow x=\frac{12}{0,3}\)
a,1/4 + 1/3:2x = -5
1/3 : 2x = -5-1/4
1/3 : 2x = -21/4
2x = 1/3 : -21 / 14
2x = -2/9
x= -2/9 : 2
x= -1/9
B, (3x-1/4) . (x+1/2) = 0
T/h1: <=> 3x-1/4 = 0
<=> 3x = 1/4
=> x= 1/12
T/h2: <=> x+1/2 =0
=> x= -1/2
Vậy x= 1/2 và x = -1/2
C, Th1:
2x-5 = 0
=> 2x= 5
=> x = 5/2
Th2:
<=> 3/2 x+9 =0
=> 3/2 x = -9
=> x= -6
TH3:
<=> 0.3x-12 = 0
0.3x=12
x= 12:0,3
=> x= 40
Vậy x= 5/2, x= -6 và x=40
Chọn đúng nhen bạn
Tìm x, biết:
a, 1/4 + 1/3 : 2x = -5
b, ( 3x - 1/4 ) . ( x + 1/2 ) = 0
c, ( 2x - 5 ) . ( 3/2x + 9 ) . ( 0,3x - 12 ) = 0
a)\(\frac{1}{4}+\frac{1}{3}:2x=-5\)
\(\frac{1}{3}:2x=-5-\frac{1}{4}\)
\(\frac{1}{3}:2x=-\frac{21}{3}\)
\(2x=\frac{1}{3}:\left(\frac{-21}{3}\right)\)
\(2x=-\frac{1}{21}\)
\(x=\frac{-1}{42}\)
b)\(\left(3x-\frac{1}{4}\right).\left(x+\frac{1}{2}\right)=0\)
\(\Rightarrow\left[\begin{array}{nghiempt}3x-\frac{1}{4}=0\\x+\frac{1}{2}=0\end{array}\right.\)\(\Rightarrow\left[\begin{array}{nghiempt}3x=\frac{1}{4}\\x=-\frac{1}{2}\end{array}\right.\)\(\Rightarrow\left[\begin{array}{nghiempt}x=\frac{1}{12}\\x=-\frac{1}{2}\end{array}\right.\)
c)\(\left(2x-5\right).\left(\frac{3}{2}x+9\right).\left(0,3x-12\right)=0\)
\(\Rightarrow\left[\begin{array}{nghiempt}2x-5=0\\\frac{3}{2}x+9=0\\0,3x-12=0\end{array}\right.\)\(\Rightarrow\left[\begin{array}{nghiempt}2x=5\\\frac{3}{2}x=-9\\0,3x=12\end{array}\right.\)\(\Rightarrow\left[\begin{array}{nghiempt}x=\frac{5}{2}\\x=-6\\x=40\end{array}\right.\)
a) 1/4 + 1/3 : 2x = -5
=> 1/3 : 2x = -5 - 1/4
=> 1/3 : 2x = -21/4
=> 2x = 1/3 : (-21/4) = -4/63
=> x = -4/63 : 2 = -2/63
1 Tìm x:
( \(3x-2\frac{1}{3}\)):( \(3\frac{1}{4}-5\frac{2}{3}+1\frac{4}{5}\)) = \(2-1\frac{1}{3}x\)
2. Tìm x:
\(\frac{x+\frac{2\left(3-x\right)}{5}}{14}-\frac{5x-4\left(x-1\right)}{24}=\frac{7x+2+\frac{9-3x}{5}}{12}+\frac{2}{3}\)
3. Tìm x:
\(\left(1+3x\right)^2-3x\left(2x+6\right)=\left(4-3x\right)\left(x+3\right)-\left(2x-1\right)^2\)
1) \(x=\frac{99}{196}\)
2) \(x=-2\)
3) \(x\approx-0,59\)