5x(3x-11)-51
5x(3x-11)-51
a) 2 phần 3x nhân 1 phần 2 = 1 phần 10
b) (2 4 phần 5x trừ 50) chia 2 phần 3 = 51
c) âm 2 phần 3x trừ 1 phần 5= 3 phần 10
d) (4,5 - 2x) nhân 1 4 phần 7 = 11 phần 14
Giúp mình nhanh nhá các bạn
a) \(\frac{2}{3}x\times\frac{1}{2}=\frac{1}{10}\Rightarrow\frac{2}{3}x=\frac{1}{5}\Rightarrow x=\frac{3}{10}\)
Tìm x, biết
a) 3 1/3x+16 3/4= -13,25 b) (2 4/5x-50) :2/3=51 c) |2x-1|=(-4)2 d)x+2/5=-11/15
e) (x-7/18).18/29=-12/29
3x-11/11 - x/3 = 3x-5/7 - 5x-3/9
Phân tích đa thức thành nhân tử
A(x) = (48x2 + 8x - 1)(3x2 + 5x +2)-4
B(x) = (12x - 1)(6x - 1)(4x - 1)(3x - 1) - 330
C(x) = 4(x2 + 11 + 30)(x2 + 22x + 120) - 3x2
D(x) = (7-x)4 + (5-x)4 - 2
E(x) = x4 - 9x3 + 28x2 - 36x +16
F(x) = x4 - 3x3 - 6x2 + 3x + 1
GPT sau:
a) ( x-1)(5x+3)= (3x - 8 )(x-1)
b) 3x ( 25x + 15 )- 35 ( 5x+3) = 0
c) (2-3x ) ( x-11)=(3x-2)(2- 5x)
Giups mk vs thank cacs bn
b) PT \(\Leftrightarrow15x\left(5x+3\right)-35\left(5x+3\right)=0\)
\(\Leftrightarrow\left(15x-35\right)\left(5x+3\right)=0\) \(\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{7}{3}\\x=-\dfrac{3}{5}\end{matrix}\right.\)
Vậy \(S=\left\{-\dfrac{3}{5};\dfrac{7}{3}\right\}\)
c) PT \(\Leftrightarrow\left(2-3x\right)\left(x-11\right)+\left(2-3x\right)\left(2-5x\right)=0\)
\(\Leftrightarrow\left(2-3x\right)\left(-9-4x\right)=0\) \(\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{2}{3}\\x=-\dfrac{9}{4}\end{matrix}\right.\)
Vậy \(S=\left\{\dfrac{2}{3};-\dfrac{9}{4}\right\}\)
a)(x-1)(5x+3)=(3x-8)(x-1)
\(\Leftrightarrow\)(x-1)(5x+3)-(3x-8)(x-1)=0
\(\Leftrightarrow\left(x-1\right)\left(5x-3-3x+8\right)=0\)
\(\Leftrightarrow\left(x-1\right)\left(2x-5\right)=0\)
\(\left[{}\begin{matrix}x-1=0\\2x-5=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=1\\x=\dfrac{5}{2}\end{matrix}\right.\)
Vậy \(x\in\left\{1;\dfrac{5}{2}\right\}\)
a) Ta có: \(\left(x-1\right)\left(5x+3\right)=\left(3x-8\right)\left(x-1\right)\)
\(\Leftrightarrow5x^2+3x-5x-3=3x^2-3x-8x+8\)
\(\Leftrightarrow5x^2-2x-3=3x^2-11x+8\)
\(\Leftrightarrow5x^2-2x-3-3x^2+11x-8=0\)
\(\Leftrightarrow2x^2+9x-11=0\)
\(\Leftrightarrow2x^2+11x-2x-11=0\)
\(\Leftrightarrow x\left(2x+11\right)-\left(2x+11\right)=0\)
\(\Leftrightarrow\left(2x+11\right)\left(x-1\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}2x+11=0\\x-1=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}2x=-11\\x=1\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=-\dfrac{11}{2}\\x=1\end{matrix}\right.\)
Vậy: \(S=\left\{-\dfrac{11}{2};1\right\}\)
b) Ta có: \(3x\left(25x+15\right)-35\left(5x+3\right)=0\)
\(\Leftrightarrow3x\cdot5\cdot\left(5x+3\right)-35\left(5x+3\right)=0\)
\(\Leftrightarrow15x\left(5x+3\right)-35\left(5x+3\right)=0\)
\(\Leftrightarrow\left(5x+3\right)\left(15x-35\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}5x+3=0\\15x-35=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}5x=-3\\15x=35\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=-\dfrac{3}{5}\\x=\dfrac{7}{3}\end{matrix}\right.\)
Vậy: \(S=\left\{-\dfrac{3}{5};\dfrac{7}{3}\right\}\)
c) Ta có: \(\left(2-3x\right)\left(x-11\right)=\left(3x-2\right)\left(2-5x\right)\)
\(\Leftrightarrow2x-22-3x^2+33x=6x-15x^2-4+10x\)
\(\Leftrightarrow-3x^2+35x-22=-15x^2+16x-4\)
\(\Leftrightarrow-3x^2+35x-22+15x^2-16x+4=0\)
\(\Leftrightarrow12x^2+19x-18=0\)
\(\Leftrightarrow12x^2+27x-8x-18=0\)
\(\Leftrightarrow3x\left(4x+9\right)-2\left(4x+9\right)=0\)
\(\Leftrightarrow\left(4x+9\right)\left(3x-2\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}4x+9=0\\3x-2=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}4x=-9\\3x=2\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=-\dfrac{9}{4}\\x=\dfrac{2}{3}\end{matrix}\right.\)
Vậy: \(S=\left\{-\dfrac{9}{4};\dfrac{2}{3}\right\}\)
\((2-3x)(x+11)=(3x-2)(2-5x)\)
\(\Leftrightarrow2x+22-3x^2-33x=6x-15x^2-4+10x\)
\(\Leftrightarrow12x^2-47x+26=0\)
\(\Leftrightarrow12x^2-8x-39x+26=0\)
\(\Leftrightarrow4x\left(3x-2\right)-13\left(3x-2\right)=0\)
\(\Leftrightarrow\left(4x-13\right)\left(3x-2\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{13}{4}\\x=\dfrac{2}{3}\end{matrix}\right.\)
Vậy...
tìm x
a) 4(18-5x)-12(3x-7)=15(2x-16)-6(x+14)
b) 5(3x+5)-4(2x-3)=5x+3(2x+12)+1
c) 2(5x-8)-3(4x-5)=4(3x-4)+11
a) \(\Rightarrow72-20x-36x+84=30x-240-6x-84\)
\(\Rightarrow80x=480\Rightarrow x=6\)
b) \(\Rightarrow15x+25-8x+12=5x+6x+36+1\)
\(\Rightarrow4x=0\Rightarrow x=0\)
c) \(\Rightarrow10x-16-12x+15=12x-16+11\)
\(\Rightarrow14x=4\Rightarrow x=\dfrac{2}{7}\)
c) (3x-2)(3x+2)-x(9x+2) <11-(5x-3)
\(\left(3x-2\right)\left(3x+2\right)-x\left(9x+2\right)< 11-\left(5x-3\right)\)
\(\Leftrightarrow\left(9x^2-4\right)-9x^2-2x< 11-5x+3\)
\(\Leftrightarrow-2x-4< 11-5x+3\)
\(\Leftrightarrow3x< 18\)
\(\Leftrightarrow x< 6\)
Vậy \(S=\left\{x|x< 6\right\}\)