Giúp vs ạ :(((((
(1-2x)^3=-8
Tính:
\(\dfrac{x^3+8}{x^2-2x+1}\) X \(\dfrac{x^2+3x+2}{1-x^2}\)
Mn giúp mik vs ạ
Lời giải:
$\frac{x^3+8}{x^2-2x+1}.\frac{x^2+3x+2}{1-x^2}=\frac{(x^3+8)(x^2+3x+2)}{(x^2-2x+1)(1-x^2)}$
$=\frac{(x+2)(x^2-2x+4)(x+1)(x+2)}{(x-1)^2(1-x)(x+1)}$
$=\frac{(x+2)^2(x^2-2x+4)}{-(x-1)^3}$
(2x-24)x8^3=8^5 giúp mk vs ạ
\(2x-24=8^5:8^3\)
\(2x-24=8^2\)
\(2x-24=64\)
\(2x=88\)
\(x=44\)
\(\left(2x-24\right).8^3=8^5\)
\(\left(2x-24\right)=8^5:8^3\)
\(\left(2x-24\right)=8^2\)
\(\left(2x-24\right)=64\)
\(2x=64+24\)
\(2x=88\)
\(\Rightarrow x=44\)
\(\left(\frac{2x-x^2}{2x^2+8}-\frac{2x^2}{x^3-2x^2+4x-8}\right)\left(\frac{2}{x^3}+\frac{1-x}{x}\right)\) ) ae giúp mik vs nhé mik cần gấp kết quả vs cách lm ngắn gọn nhất của bài này ạ
Tìm số tự nhiên x biết:
(x+2)-2=0
(x+3)+1=7
(3x-4)+4=12
(5x+4)-1=13
(4x-8)-3=5
8-(2x-4)=2
7+(5x+2)=14
5-(3x-11)=1
Giúp e vs ạ(Vui lòng trình bày ạ)
\(\left(x+2\right)-2=0\)
\(\Rightarrow x+2-2=0\)
\(\Rightarrow x=0\)
\(\left(x+3\right)+1=7\)
\(\Rightarrow x+3+1=7\)
\(\Rightarrow x+4=7\)
\(\Rightarrow x=3\)
\(\left(3x-4\right)+4=12\)
\(\Rightarrow3x-4+4=12\)
\(\Rightarrow3x=12\)
\(\Rightarrow x=4\)
\(\left(5x+4\right)-1=13\)
\(\Rightarrow5x+4-1=13\)
\(\Rightarrow5x+3=13\)
\(\Rightarrow5x=10\)
\(\Rightarrow x=2\)
\(\left(4x-8\right)-3=5\)
\(\Rightarrow4x-8-3=5\)
\(\Rightarrow4x-11=5\)
\(\Rightarrow4x=16\)
\(\Rightarrow x=4\)
\(8-\left(2x+4\right)=2\)
\(\Rightarrow8-2x-4=2\)
\(\Rightarrow4-2x=2\)
\(\Rightarrow2x=2\)
\(\Rightarrow x=1\)
\(7+\left(5x+2\right)=14\)
\(\Rightarrow7+5x+2=14\)
\(\Rightarrow9+5x=14\)
\(\Rightarrow5x=5\)
\(\Rightarrow x=1\)
\(5-\left(3x-11\right)=1\)
\(\Rightarrow5-3x+11=1\)
\(\Rightarrow16-3x=1\)
\(\Rightarrow3x=15\)
\(\Rightarrow x=5\)
tìm x
(3x-1) (-1/2x +5)=0
(3/4-x)3 =-8
| 2x -1|= -42
giải giúp mik vs ạ
c ơn nhiều
1) (3x-1)(-1/2x+5)=0
TH1: 3x-1=0
3x = 1
x = 1/3
TH2: -1/2x+5=0
-1/2x =-5
x = 10
2) (3/4-x)^3=-8
(3/4-x)^3=(-2)^3
=> 3/4-x=-2
x=3/4+2
x= 11/4
3) |2x-1|=-4^2
|2x-1|=16
=> 2x-1=-16 hoặc 2x-1=16
TH1: 2x-1=-16
2x =-15
x = -15/2
TH2: 2x-1=16
2x =17
x = 17/2
phân tích đa thức thành nhân tử:
2x^2y+4xy^2+2y^3-8
giúp tui vs ạ
\(2x^2y+4xy^2+2y^3-8\)
\(=2y\left(x^2+2xy+y^2\right)-8\)
\(=2y\left(x+y\right)^2-8\)
\(=2\left[y\left(x+y\right)^2-4\right]\)
m.n giúp em giải 8 bài này vs ạ!
TÍNH
1.(√2x - y)²
2.(√2x + √8y)²
3.(x + 1/6y) + 3)²
4.(2x - 3).(2x + 3)
5.(3x - 1/2y).(3x + 1/3y)
6.(x² - 4).( x² + 4)
7.(x + y)²+(x - y)²
8.(2x + 3)² - (x + 1)²
Cảm ơn anh chị ạ!!!
2x/3y = -1/3 và 2x + 3y^2 = 161/4 Giúp mik vs ạ
\(\dfrac{2x}{3y}=-\dfrac{1}{3}\\ \Rightarrow3y=2x:-\dfrac{1}{3}=\dfrac{2x.3}{-1}=-6x\\ \Rightarrow y=-\dfrac{6x}{3}=-2x\)
Thế \(y=-2x\) vào \(2x+3y^2=\dfrac{161}{4}\) được:
\(2x+3.\left(-2x\right)^2=\dfrac{161}{4}\\ \Leftrightarrow2x+12x^2-\dfrac{161}{4}=0\\ \Leftrightarrow48x^2+8x-161=0\\ \Leftrightarrow\left(48x^2+92x\right)+\left(-84x-161\right)=0\\ \Leftrightarrow4x\left(12x+23\right)-7\left(12x+23\right)=0\\ \Leftrightarrow\left(4x-7\right)\left(12x+23\right)=0\\ \Leftrightarrow\left\{{}\begin{matrix}x=\dfrac{7}{4}\Rightarrow y=-\dfrac{2.7}{4}=-\dfrac{7}{2}\\x=-\dfrac{23}{12}\Rightarrow y=-2.-\dfrac{23}{12}=\dfrac{23}{6}\end{matrix}\right.\)
Vậy phương trình có nghiệm \(\left\{x;y\right\}=\left\{\dfrac{7}{4};-\dfrac{7}{2}\right\}\) hoặc \(\left\{x;y\right\}=\left\{-\dfrac{23}{12};\dfrac{23}{6}\right\}\)
(2x + 1) ^ 2 >= 4x ^ 2 - 3 Giải giúp vs ạ
\(\left(2x+1\right)^2\ge4x^2-3\)
\(\Leftrightarrow4x^2+2x+2x+1\ge4x^2-3\)
\(\Leftrightarrow4x^2-4x^2+2x+2x\ge-3-1\)
\(\Leftrightarrow4x\ge-4\\ \Leftrightarrow x\ge-1\)
Vậy phương trình có tập nghiệm là:\(S=\left\{x|x\ge-1\right\}\)
\(\left(2x+1\right)^2\ge4x^2-3\)
\(\Leftrightarrow4x^2+4x+1\ge4x^2-3\)
\(\Leftrightarrow4x^2-4x^2+4x\ge-3-1\)
\(\Leftrightarrow4x\ge-4\)
\(\Leftrightarrow x\ge-1\)
\(\left(2x+1\right)^2\ge4x^2-3\\ \Leftrightarrow4x^2+4x+1-4x^2+3\ge0\\ \Leftrightarrow4x\ge-4\\ \Leftrightarrow x\ge-1\)
Vậy: S= [-1; +∞)
e) 5.(3x + 8) –7.(2x + 3) = 16
GIúp mk vs ạ :D
5.(3x+8)-7.(2x+3)=16
=> 15x+40-14x-21=16
=>(15x-14x)+(40-21)
=> x+19=16
=>x=-3. Vậy x=-3
k cho mik nha
Chúc bạn hok tốt
\(5\left(3x+8\right)-7\left(2x+3\right)=16\)
\(15x+40-14x-21=16\)
\(x+19=16\)
\(x+19-16=0\)
\(x+3=0\)
\(x=-3\)