tim x:
15x2-12x=0
bài 2: tìm x:
a) (4x4+3x3)÷(−x3)+(15x2+6x)÷3x=0
b)(x2−12x)÷2x−(3x−1)2÷(3x−1)=0
Bài 2: Tìm x
a)ĐKXĐ: \(x\ne0\)
Ta có: \(\left(4x^4+3x^3\right):\left(-x^3\right)+\left(15x^2+6x\right):3x=0\)
\(\Leftrightarrow\frac{-x^3\left(4x+3\right)}{x^3}+\frac{3x\left(5x+2\right)}{3x}=0\)
\(\Leftrightarrow-4x-3+5x+2=0\)
\(\Leftrightarrow x-1=0\)
hay x=1(nhận)
Vậy: x=1
b) ĐKXĐ: \(x\notin\left\{0;\frac{1}{3}\right\}\)
Ta có: \(\left(x^2-12x\right):2x-\left(3x-1\right)^2:\left(3x-1\right)=0\)
\(\Leftrightarrow\frac{x\left(x-12\right)}{2x}-\frac{\left(3x-1\right)^2}{\left(3x-1\right)}=0\)
\(\Leftrightarrow\frac{x-12}{x}-3x+1=0\)
\(\Leftrightarrow\frac{x-12}{x}=3x-1\)
\(\Leftrightarrow x-12=x\left(3x-1\right)\)
\(\Leftrightarrow3x^2-x+x-12=0\)
\(\Leftrightarrow3x^2-12=0\)
\(\Leftrightarrow3x^2=12\)
\(\Leftrightarrow x^2=4\)
\(\Leftrightarrow\left[{}\begin{matrix}x=2\left(nhận\right)\\x=-2\left(nhận\right)\end{matrix}\right.\)
Vậy: \(x\in\left\{2;-2\right\}\)
Tìm x:
1. ( 4x4 + 3x3 ) : ( -x3) + ( 15x2 + 6x ) : 3x = 0
2. ( 25x2 - 10x) : ( -5x) - 3( x-2) = 4
3. ( 42x3 - 12x ) : ( -6x) + 7x ( x+2) = 8
`1)<=> -4x-3 + 5x+ 2 =0`
`<=> 5x-4x = -2+3`
`<=> x =1`
`2)<=> -5x +2-3x+6 =4`
`<=> -5x-3x = 4-6-2`
`<=> -8x=-4`
`<=> x=1/2`
`3) <=> -7x^2 +2 +7x^2 +14x =8`
`<=> 14x +2 =8`
`<=> 14x = 6`
`<=> x=3/7`
tim x (X/2+3)(5-6X)+(12X-2)(X/4+3)=0
tim x 8x^3 + 12x^2 + 6x - 26 = 0
\(8x^3+12x^2+6x-26=0\)
<=> \(4x^3+6x^2+3x-13=0\)
<=> \(4x^3-4x^2+10x^2-10x+13x-13=0\)
<=> \(4x^2\left(x-1\right)+10x\left(x-1\right)+13\left(x-1\right)=0\)
<=> \(\left(x-1\right)\left(4x^2+10x+13\right)=0\)
<=> \(x-1=0\)
<=> \(x=1\)
Vậy...
tim x biet 4x2 -12x-7=0
4x2 - 12x -7 = 0
<=> 4x2 -14x +2x -7 = 0
<=> 2x(2x-7) + (2x-7) = 0
<=> (2x-7)(2x+1) = 0
<=> 2x-7 = 0 hoặc 2x+1 = 0
<=> 2x = 7 hoặc 2x = -1
<=> x= \(\frac{7}{2}\)hoặc x= \(\frac{-1}{2}\)
Vậy tập nghiệm của phương trình là S={\(\frac{7}{2}\);\(\frac{-1}{2}\)}
(x^2-1/2x):2x-(3x-1)^2.(3x-1)=0
(4x^4 + 3x3) : (-x^3) + (15x2 + 6x) : 3x =0
Ta có: \(\dfrac{4x^4+3x^3}{-x^3}+\dfrac{15x^2+6x}{3x}=0\)
\(\Leftrightarrow-4x-3+5x+2=0\)
\(\Leftrightarrow x-1=0\)
hay x=1
15x2 + 30 = 0
(2x – 1 )2 .4 = 1
Tìm giá trị của x?
\(15x^2+30=0\\ \Rightarrow x^2+2=0\left(vô.lí\right)\\ \Rightarrow x\in\varnothing\)
\(\left(2x-1\right)^2.4=1\\ \Rightarrow\left(2x-1\right)^2=\dfrac{1}{4}\\ \Rightarrow\left[{}\begin{matrix}2x-1=\dfrac{1}{2}\\2x-1=-\dfrac{1}{2}\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}x=\dfrac{3}{4}\\x=\dfrac{1}{4}\end{matrix}\right.\)
tim x
4X2 - 12X=0
4x2-12x=0
=>4x(x-3)=0
=>x=0 hoặc x-3=0
=>x=0 hoặc x=3
tim x biet
16x^3 - 12x^2 + 3x - 7 = 0
tim x
a)4x(x-7)-4x2=56
b)12x(3x-2)-(4-6x)=0
c)4(x-5)-(5-x)2=0
a: Ta có: \(4x\left(x-7\right)-4x^2=56\)
\(\Leftrightarrow4x^2-7x-4x^2=56\)
hay x=-8
b: Ta có: \(12x\left(3x-2\right)-\left(4-6x\right)=0\)
\(\Leftrightarrow36x^2-24x-4+6x=0\)
\(\Leftrightarrow36x^2-18x-4=0\)
\(\text{Δ}=\left(-18\right)^2-4\cdot36\cdot\left(-4\right)=900\)
Vì Δ>0 nên phương trình có hai nghiệm phân biệt là:
\(\left\{{}\begin{matrix}x_1=\dfrac{18-30}{72}=\dfrac{-1}{6}\\x_2=\dfrac{18+30}{72}=\dfrac{2}{3}\end{matrix}\right.\)
c: Ta có: \(4\left(x-5\right)-\left(x-5\right)^2=0\)
\(\Leftrightarrow\left(x-5\right)\left(4-x+5\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x=5\\x=9\end{matrix}\right.\)