(3x-6).3=3^4
Tính :
1) 4(3x+4)
2) 4/3(5/3x+6)
3)(4/3x+7).5+2
4)(3/7x-6).(-7)+3x
1, 4[3x + 4] = 12x + 16
2, 4/3[5/3x + 6] = 20/9x + 12
3, [4/3x + 7]. 5 + 2 = 20/3x + 35 + 2 = 20/3x + 37
4, [3/7x - 6][-7] + 3x = -3x + 42 + 3x = 42
Tìm x:
1) -3.(1-2x) - 4.(1+3x) = -5x + 5
2) 3.(2x - 5) - 6.(1 - 4x) = -3x + 7
3) (1 - 3x) - 2.(3x - 6) = -4x - 5
4) x.(4x - 3) - 2x.(2x - 1) = 5x - 7
5) 3x.(2x - 1) - 6x.(x + 2) = -3x + 4
6) (1 - 2x).3 - 4.(6x - 1) = 7x - 5
7) 6x - 3.(1 - 4x) - 5.(x + 1) = 2x + 7
8) 6.(1 - 3x) - 3.(2x + 5) = -10x + 7
9) 3x.(1 - 2x) + 6x^2 - 7x = 8.(1 - 2x) - 9
10) 2x.(1 + 3x) - 3x.(4 + 2x) = 3x - 4
* Trả lời:
\(\left(1\right)\) \(-3\left(1-2x\right)-4\left(1+3x\right)=-5x+5\)
\(\Leftrightarrow-3+6x-4-12x=-5x+5\)
\(\Leftrightarrow6x-12x+5x=3+4+5\)
\(\Leftrightarrow x=12\)
\(\left(2\right)\) \(3\left(2x-5\right)-6\left(1-4x\right)=-3x+7\)
\(\Leftrightarrow6x-15-6+24x=-3x+7\)
\(\Leftrightarrow6x+24x+3x=15+6+7\)
\(\Leftrightarrow33x=28\)
\(\Leftrightarrow x=\dfrac{28}{33}\)
\(\left(3\right)\) \(\left(1-3x\right)-2\left(3x-6\right)=-4x-5\)
\(\Leftrightarrow1-3x-6x+12=-4x-5\)
\(\Leftrightarrow-3x-6x+4x=-1-12-5\)
\(\Leftrightarrow-5x=-18\)
\(\Leftrightarrow x=\dfrac{18}{5}\)
\(\left(4\right)\) \(x\left(4x-3\right)-2x\left(2x-1\right)=5x-7\)
\(\Leftrightarrow4x^2-3x-4x^2+2x=5x-7\)
\(\Leftrightarrow-x-5x=-7\)
\(\Leftrightarrow-6x=-7\)
\(\Leftrightarrow x=\dfrac{7}{6}\)
\(\left(5\right)\) \(3x\left(2x-1\right)-6x\left(x+2\right)=-3x+4\)
\(\Leftrightarrow6x^2-3x-6x^2-12x=-3x+4\)
\(\Leftrightarrow-15x+3x=4\)
\(\Leftrightarrow-12x=4\)
\(\Leftrightarrow x=-\dfrac{1}{3}\)
Bài3
a, (3x -6 ) + 3 = 32
b, (3x-6) - 3 = 32
c, (3x-6) . 3 = 32
d, (3x-6) ; 3 = 32
e, (3x- 24) . 73 = 2. 74
f | x | = |-7|
g, | x +1| = 2
h, | x+1 | = 3 và x+1 < 0
i,x = | -2 | =0
j, 4 . ( 3x -4 ) -2 = 18
(3x-6)+3=3^2
3x+3=3^2
3*(x+1)=9
x+1=9:3
x+1=3
x=3-1=2
Giải phương trình, x>0
\(\frac{\left(x^3+3x^2\sqrt{x^3-3x+6}\right)\left(3x-x^3-2\right)}{2+\sqrt{x^3-3x+6}}=4\left[2\sqrt{\left(x^3-3x+6\right)^3}-\left(x^3-3x+6\right)^2\right]\)
bài này chắc đặt \(\sqrt{x^3-3x+6}\)cho nó gọn thôi
Giải phương trình, x>0
\(\frac{\left(x^3+3x^2\sqrt{x^3-3x+6}\right)\left(3x-x^3-2\right)}{2+\sqrt{x^3-3x+6}}=4\left[2\sqrt{\left(x^3-3x+6\right)^3}-\left(x^3-3x+6\right)^2\right]\)
d) (3x – 5)(7 – 5x) – (5x + 2)(2 – 3x) = 4 g) 3(2x - 1)(3x - 1) - (2x - 3)(9x - 1) =0 j) (2x – 1)(3x + 1) – (4 – 3x)(3 – 2x) = 3 k) (2x + 1)(x + 3) – (x – 5)(7 + 2x) = 8 m) 2(3x – 1)(2x + 5) – 6(2x – 1)(x + 2) = - 6
g: Ta có: \(3\left(2x-1\right)\left(3x-1\right)-\left(2x-3\right)\left(9x-1\right)=0\)
\(\Leftrightarrow3\left(6x^2-5x+1\right)-\left(18x^2-29x+3\right)=0\)
\(\Leftrightarrow18x^2-15x+3-18x^2+29x-3=0\)
\(\Leftrightarrow14x=0\)
hay x=0
giải phương trình sau
2, (x+3)(x+5)+(x+3)(3x-4)=0
3, (x+6)(3x-1)+x+6=0
4, (x+4)(5x+9)-x-4=0
5, (1-x)(5x+3)=(3x-7)(x-1)
6, 2x(2x-3)=(3-2x)(2-5x)
\(2.\left(x+3\right)\left(x+5\right)+\left(x+3\right)\left(3x-4\right)=0\\ \Leftrightarrow x^2+5x+3x+15+3x^2-4x+9x-12=0\\ \Leftrightarrow x^2+3x^2+5x+3x-4x+9x+15-12=0\\\Leftrightarrow 4x^2+13x+3=0\\\Leftrightarrow 4\left(x^2+\frac{13}{4}x+\frac{3}{4}\right)=0\\\Leftrightarrow x^2+\frac{13}{4}x+\frac{3}{4}=0\\ \Leftrightarrow x^2+\frac{1}{4}x+3x+\frac{3}{4}=0\\\Leftrightarrow x\left(x+\frac{1}{4}\right)+3\left(x+\frac{1}{4}\right)=0\\\Leftrightarrow \left(x+3\right)\left(x+\frac{1}{4}\right)=0\\\Leftrightarrow \left[{}\begin{matrix}x+3=0\\x+\frac{1}{4}=0\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=-3\\x=-\frac{1}{4}\end{matrix}\right.\)
Vậy tập nghiệm của phương trình trên là: \(S=\left\{-3;-\frac{1}{4}\right\}\)
\(3.\left(x+6\right)\left(3x-1\right)+x+6=0\\ \Leftrightarrow3x^2-x+18x-6+x+6=0\\ \Leftrightarrow3x^2+18x=0\\ \Leftrightarrow3x\left(x+6\right)=0\\\Leftrightarrow \left[{}\begin{matrix}3x=0\\x+6=0\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=0\\x=-6\end{matrix}\right.\)
Vậy tập nghiệm của phương trình trên là \(S=\left\{0;-6\right\}\)
\(4.\left(x+4\right)\left(5x+9\right)-x-4=0\\\Leftrightarrow 5x^2+9x+20x+36-x-4=0\\ \Leftrightarrow5x^2+28x+32=0\\\Leftrightarrow 5\left(x^2+\frac{28}{5}x+\frac{32}{5}\right)=0\\ \Leftrightarrow x^2+\frac{28}{5}x+\frac{32}{5}=0\\\Leftrightarrow x^2+\frac{8}{5}x+4x+\frac{32}{5}=0\\ \Leftrightarrow x\left(x+\frac{8}{5}\right)+4\left(x+\frac{8}{5}\right)=0\\\Leftrightarrow \left(x+4\right)\left(x+\frac{8}{5}\right)=0\\ \left[{}\begin{matrix}x+4=0\\x+\frac{8}{5}=0\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=-4\\x=-\frac{8}{5}\end{matrix}\right.\)
Vậy tập nghiệm của phương trình trên là:\(S=\left\{-4;-\frac{8}{5}\right\}\)
tìm x, biết
1. -11/2x + 1= 1/3x - 1/4
2. 2x- 2/3 - 7x = 3/2 - 1
3. 3/2x - 2/5 = 1/3x - 1/4
4. 2/3 - 5/3x= 7/10x + 5/6
5. 2x -1/4 = 5/6 - 1/2x
6. 3x - 5/3 = x - 1/4
7. - 5/6 + 3x = 2/3 - 1/2x
8. 1/2 ( x + 2 ) - 4( x - 1/4 ) = 1/2x
9. 5/2( x - 3/5 ) - 1/10 = x-3
10. -4/3( x - 1/4 ) = 3/2( 2x - 1 )
Giúp mk với !!!
Bài 1:
- \(\dfrac{11}{2}x\) + 1 = \(\dfrac{1}{3}x-\dfrac{1}{4}\)
- \(\dfrac{11}{2}\)\(x\) - \(\dfrac{1}{3}\)\(x\) = - \(\dfrac{1}{4}\) - 1
-(\(\dfrac{33}{6}\) + \(\dfrac{2}{6}\))\(x\) = - \(\dfrac{5}{4}\)
- \(\dfrac{35}{6}\)\(x\) = - \(\dfrac{5}{4}\)
\(x=-\dfrac{5}{4}\) : (- \(\dfrac{35}{6}\))
\(x\) = \(\dfrac{3}{14}\)
Vậy \(x=\dfrac{3}{14}\)
Bài 2: 2\(x\) - \(\dfrac{2}{3}\) - 7\(x\) = \(\dfrac{3}{2}\) - 1
2\(x\) - 7\(x\) = \(\dfrac{3}{2}\) - 1 + \(\dfrac{2}{3}\)
- 5\(x\) = \(\dfrac{9}{6}\) - \(\dfrac{6}{6}\) + \(\dfrac{4}{6}\)
- 5\(x\) = \(\dfrac{7}{6}\)
\(x\) = \(\dfrac{7}{6}\) : (- 5)
\(x\) = - \(\dfrac{7}{30}\)
Vậy \(x=-\dfrac{7}{30}\)
Bài 3: \(\dfrac{3}{2}\)\(x\) - \(\dfrac{2}{5}\) = \(\dfrac{1}{3}x\) - \(\dfrac{1}{4}\)
\(\dfrac{3}{2}\)\(x\) - \(\dfrac{1}{3}x\) = \(-\dfrac{1}{4}\) + \(\dfrac{2}{5}\)
(\(\dfrac{9}{6}\) - \(\dfrac{2}{6}\))\(x\) = \(\dfrac{-5}{20}\) + \(\dfrac{8}{20}\)
\(\dfrac{7}{6}x\) = \(\dfrac{3}{20}\)
\(x\) = \(\dfrac{3}{20}\) : \(\dfrac{7}{6}\)
\(x\) = \(\dfrac{9}{70}\)
Vậy \(x=\dfrac{9}{70}\)
`4) | 3-2x| =4/3
5) | x-1| = 2x+3
6) | 1/3x-4/3| =1-4/3x
4 ) \(\left|3-2x\right|=\frac{4}{3}\)
+) \(3-2x=\frac{4}{3}\)
\(2x=3-\frac{4}{3}\)
\(2x=\frac{5}{3}\)
\(x=\frac{5}{3}:2\)
\(x=\frac{5}{3}.\frac{1}{2}\)
\(x=\frac{10}{3}\)
+) \(3-2x=-\frac{4}{3}\)
\(2x=3--\frac{4}{3}\)
\(2x=\frac{13}{3}\)
\(x=\frac{13}{3}:2\)
\(x=\frac{13}{3}.\frac{1}{2}\)
\(x=\frac{26}{3}\)
Rồi tiếp tục giải đi mk cũng giống @Đinh Tuấn Việt
Tương tự mấy bài dưới thôi bạn, dài lắm mình ngại làm
rut gon
a,3x(2x-7)-3x(4x-5)
b,(-7x+8)(-2x+3)-7x(2x-4)
c,(2x-3)(3x2-2x+4)-(2x-3)(3x+4)
d,(-2+7)(3x-6)-(4x-5)(2x-6)