tìm x biết: 2x^2+12+2x(4-x)=0
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Tìm số nguyên x biết: a) x + 12 = 4; b) 19 - x = 0; c) 2x - 4 = -12;d) 2x- (-2) = 6
a)x=4-12=-8
b)x=19-0=19
c)x=-12+4:2=-4
d)x=6+(-2):2=2
Bài 13: Tìm x biết: a) (x-2)(x-3)-D0. b) (x-3)(x-4)-0. c) (x-7)(6-x)=0. d) (x-3)(x-13)=0. The Bài 14: Tìm x biết: a) (12-x)(2-x)=0. b) (x-33)(11-x)=0. c) (21-x)(12-x)=0. d) (50-x)(x-150) =0. Bài 15: Tìm x biết: a) 2x +x = 45. b) 2x +7x = 918. c) 2x+3x 60+5. d) 11x+22x 33.2.
Tìm x, biết :
a/ (x – 3)2 – x(x – 4) = 5
b) x(x – 6) + 2x – 12 = 0
\(a,\left(x-3\right)^2-x\left(x-4\right)=5\\ \Rightarrow x^2-6x+9-x^2+4x=5\\ \Rightarrow-2x=-4\\ \Rightarrow x=2\\ b,x\left(x-6\right)+2x-12=0\\ \Rightarrow x\left(x-6\right)+2\left(x-6\right)=0\\ \Rightarrow\left(x+2\right)\left(x-6\right)=0\\ \Rightarrow\left[{}\begin{matrix}x=-2\\x=6\end{matrix}\right.\)
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Tìm x biết
a) (x+2).(x+3) - (x-2).(x+5)=10
b) (3x+2). (2x+9) - (x+2). (8x+11)=(x+1).(3-2x)
c) 3.(2x-1).(3x-1)-(2x-3).(9x-1)=0
d) (5x-8).(4x-5)-(3x-4).(2x+12)=12
a)(x+2).(x+3)-(x-2).(x+5)=10
( x^2 +3x+2x+6)-(x^2 +5x-2x-10)=10
x^2 +3x+2x+6-x^2 -5x+2x+10-10=0
2x+6=0
2x=-6
x=-3
Tìm x biết a) 3x^2+x)4-3x)=12 b)3x^2-2x-1=0
b: \(3x^2-2x-1=0\)
=>\(3x^2-3x+x-1=0\)
=>\(\left(x-1\right)\left(3x+1\right)=0\)
=>\(\left[{}\begin{matrix}x-1=0\\3x+1=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=1\\x=-\dfrac{1}{3}\end{matrix}\right.\)
a: Bạn ghi lại đề đi bạn
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Tìm x,y biết :
|x-4|+|6-x|=0
|x+1|-|x-2|=0
|x+2|-|x-3|=0
|x-2|-|x-3|=0
|2x-1|-|x+1|=0
4x-6+2x=12
|x - 4| + |6 - x| = 0
|x - 4| ; |6 - x| \(\ge\) 0
=> |x - 4| = |6 - x| = 0
|x - 4| = 0 => x= 4
|6 - x| = 0 => x= 6
Vì \(4\ne6\) n ê n không có giá trị của x
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1) Tìm x biết :
a) 3/4-(1/2:x+1/2)=3/5
b)3x.(1/2x-1)=0
c)(4-x).(2x+3)=0
d)4/-3=-12/x
e)4x/-3=12/-x
a) \(\frac{3}{4}-\left(\frac{1}{2}:x+\frac{1}{2}\right)=\frac{3}{5}\)
\(\Leftrightarrow\frac{1}{2}:x+\frac{1}{2}=\frac{3}{4}-\frac{3}{5}\)
\(\Leftrightarrow\frac{1}{2}:x+\frac{1}{2}=\frac{15}{20}-\frac{12}{20}\)
\(\Leftrightarrow\frac{1}{2}:x+\frac{1}{2}=\frac{13}{20}\)
\(\Leftrightarrow\frac{1}{2}:x=\frac{13}{20}-\frac{1}{2}\)
\(\Leftrightarrow\frac{1}{2}:x=\frac{13}{20}-\frac{10}{20}\)
\(\Leftrightarrow\frac{1}{2}:x=\frac{3}{20}\)
\(\Leftrightarrow x=\frac{1}{2}:\frac{3}{20}\)
\(\Leftrightarrow x=\frac{1}{2}.\frac{20}{3}=\frac{10}{3}\)
Vậy: \(x=\frac{10}{3}\)
b) \(3x.\left(\frac{1}{2}.x-1\right)=0\)
\(\Leftrightarrow\orbr{\begin{cases}3x=0\\\frac{1}{2}x-1=0\end{cases}\Leftrightarrow\orbr{\begin{cases}x=0\\\frac{1}{2}x=1\end{cases}\Leftrightarrow}\orbr{\begin{cases}x=0\\x=1:\frac{1}{2}\end{cases}\Leftrightarrow}\orbr{\begin{cases}x=0\\x=2\end{cases}}}\)
Vậy: \(x\in\left\{0;2\right\}\)
c) \(\left(4-x\right)\left(2x+3\right)=0\)
\(\Leftrightarrow\orbr{\begin{cases}4-x=0\\2x+3=0\end{cases}\Leftrightarrow\orbr{\begin{cases}x=4\\2x=3\end{cases}\Leftrightarrow}\orbr{\begin{cases}x=4\\x=\frac{3}{2}\end{cases}}}\)
Vậy: \(x\in\left\{4;\frac{3}{2}\right\}\)
d) \(\frac{4}{-3}=\frac{-12}{x}\)
\(\Leftrightarrow4x=\left(-12\right).\left(-3\right)\)
\(\Leftrightarrow4x=36\)
\(\Leftrightarrow x=9\)
Vậy: \(x=9\)
e) \(\frac{4x}{-3}=\frac{12}{-x}\)
\(\Leftrightarrow4x.\left(-x\right)=12.\left(-3\right)\)
\(\Leftrightarrow-4x^2=-36\)
\(\Leftrightarrow x^2=9\)
\(\Leftrightarrow\orbr{\begin{cases}x=3\\x=-3\end{cases}}\)
Vậy: \(x\in\left\{3;-3\right\}\)
a,Ta có: 3/4-(1/2:x+1/2)=3/5
-(1/2:x+1/2)=3/5-3/4
-(1/2:x+1/2)=-3/20
1/2:x+1/2=3/20
1/2:x=3/20-1/2
1/2:x=-7/20
x=1/2:-7/20
x=-10/7
b,Ta có: 3x.(1/2x-1)=0
Với 3x=0 =>x=0
vói1/2x-1=0
a)\(\frac{3}{4}-\left(\frac{1}{2}:x+\frac{1}{2}\right)=\frac{3}{5}\)
\(\Leftrightarrow\frac{1}{2}:x+\frac{1}{2}=\frac{3}{20}\)
\(\Leftrightarrow\frac{1}{2}:x=\frac{-7}{20}\Leftrightarrow x=-\frac{10}{7}\)
b) \(3x\left(\frac{1}{2}x-1\right)=0\)
\(\Leftrightarrow\orbr{\begin{cases}3x=0\\\frac{1}{2}x-1=0\end{cases}}\Leftrightarrow\orbr{\begin{cases}x=0\\\frac{1}{2}x=1\end{cases}}\Leftrightarrow\orbr{\begin{cases}x=0\\x=2\end{cases}}\)
Vậy x = 0 hoặc x = 2
c) \(\left(4-x\right)\left(2x+3\right)=0\)
\(\Leftrightarrow\orbr{\begin{cases}4-x=0\\2x+3=0\end{cases}}\Leftrightarrow\orbr{\begin{cases}x=4\\2x=-3\end{cases}}\Leftrightarrow\orbr{\begin{cases}x=4\\x=-\frac{3}{2}\end{cases}}\)
Vậy x = 4 hoặc x = -3/2
d) \(\frac{4}{-3}=-\frac{12}{x}\Leftrightarrow4x=36\Leftrightarrow x=9\)
e) \(\frac{4x}{-3}=\frac{12}{-x}\)
\(\Leftrightarrow4x\left(-x\right)=-36\)
\(\Leftrightarrow x\left(-x\right)=-9\)
\(\Leftrightarrow-x^2=-9\)
\(\Leftrightarrow-x^2=-3^2\Leftrightarrow-x=-3\Leftrightarrow x=3\)
Tìm số nguyên x, biết.
[(8x - 12) : 4] . 3 mũ 3 = 3 mũ 6
41-2 x+1=9
5 mũ 2x – 3 – 2 . 5mũ 2 = 5mũ 2 . 3
3 mũ 2x-4 - x mũ 0 = 8
30 - [4(x - 2) + 15] = 3
65 – 4 mũ x+2 = 2014mũ 0
740:(x + 10) = 10 mũ 2 – 2.13
120 + 2.(3x - 17) = 214
5 mũ 2x – 3 – 2 . 5 mũ 2 = 5mũ 2 . 3
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Bài 2: Tìm x biết:
a) x.(x + 1) – x² + 2 = 0
b) 2.(3x + 2) – (2x + 12) = 0
c) 2x³(2x – 3) – x²(4x² – 6x + 2) = 0
d) (3x + 2)(x – 1) – 3(x + 1)(x – 2) = 4