1 phần 3-x - 1 phan 3+x >0
-3x +4 phan 2x-3 < -2
giup mk vs
Bai 1 Phan tich da thuc thanh nhan tu
x^3 + 3x- 3xy- 3y
Bai 2 Tim x
( 2x - 1) ( 2x + 1) - 4 ( x ^2 +x ) = 16
cac bn lam on giup mink di ma
1) Tim x
a) 3x(x-1)+x-1=0
b)2(x+3)-x^2-3x=0
làm tương tự như bài này nè!
x(x-2)+x-2=0
=>x*((x-2)-x-3)=0
=>(x-2)(x+10=0
hoac x-3=0 =>x=3
hoac 5x-1=0 =>x=1 phan 5
vậy x = 1 phần 5 ;x=3
hoac 5x-1=0 => x=1 phan 5
a)\(3x\left(x-1\right)+x-1=0\Leftrightarrow\left(x-1\right)\left(3x-1\right)=0\Leftrightarrow\hept{\begin{cases}x-1=0\\3x-1=0\end{cases}\Leftrightarrow\hept{\begin{cases}x=1\\x=\frac{1}{3}\end{cases}}}\)
\(S=\left\{1;\frac{1}{3}\right\}\)
b)\(2\left(x+3\right)-x^2-3x=0\)
\(\Leftrightarrow2\left(x+3\right)-x\left(x+3\right)=0\)
\(\Leftrightarrow\left(2-x\right)\left(x+3\right)=0\Leftrightarrow\hept{\begin{cases}2-x=0\\x+3=0\end{cases}\Leftrightarrow\hept{\begin{cases}x=2\\x=-3\end{cases}}}\)
\(S=\left\{2;-3\right\}\)
bai 1
a, A = / -0 ,75 / -2 và 1 phan 3 + 1 phần 4
b, B = / x + 1 phan 2 / - /x+2 / + / x -3 phần 4 /
khi x = - 1 phần 2
\(1,\)
\(2x\left(x-3\right)-\left(3-x\right)=0\)
\(\Leftrightarrow2x\left(x-3\right)+\left(x-3\right)=0\)
\(\Leftrightarrow\left(2x+1\right)\left(x-3\right)=0\)
\(\Leftrightarrow\orbr{\begin{cases}2x+1=0\\x-3=0\end{cases}}\)
\(\Leftrightarrow\orbr{\begin{cases}x=\frac{-1}{2}\\x=3\end{cases}}\)
\(2,\)
\(3x\left(x+5\right)-6\left(x+5\right)=0\)
\(\Leftrightarrow\left(3x-6\right)\left(x+5\right)=0\)
\(\Leftrightarrow\orbr{\begin{cases}3x-6=0\\x+5=0\end{cases}}\)
\(\Leftrightarrow\orbr{\begin{cases}x=2\\x=-5\end{cases}}\)
\(3,\)
\(x^4-x^2=0\)
\(\Leftrightarrow x^2\left(x^2-1\right)=0\)
\(\Leftrightarrow\orbr{\begin{cases}x^2=0\\x^2-1=0\end{cases}}\)
\(\Leftrightarrow\orbr{\begin{cases}x=0\\x=\pm1\end{cases}}\)
\(4,\)
\(x^2-2x=0\)
\(\Leftrightarrow x\left(x-2\right)=0\)
\(\Leftrightarrow\orbr{\begin{cases}x=0\\x-2=0\end{cases}}\)
\(\Leftrightarrow\orbr{\begin{cases}x=0\\x=2\end{cases}}\)
\(5,\)
\(x\left(x+6\right)-10\left(x-6\right)=0\)
\(\Leftrightarrow x^2+6x-10x+60=0\)
\(\Leftrightarrow x^2-4x+60=0\)
\(\Leftrightarrow x^2-4x+4+56=0\)
\(\Leftrightarrow\left(x-2\right)^2=-56\)(Vô lý)
=> Phương trình vô nghiệm
1) - Phan tich cac da thuc sau thanh nhan tu :
a) 14x2y2 - 21xy2 + 28x2y d) 2 phan 7 x(3y -1 )-2 phan 7y (3y-1)
b) x3 -3x2 + 3x- 1 e) (x+y)2-4x2
c) 27x2+1phan 8 f) (x+y)3-(x-y)3
2) tim x biet
a) x2(x+1)+2x(x+1)=0 b) x(3x-2)-5(2-3x)=0
c) 4 phan 9 -25x2=0 d) x2-x+phan4=0
3) tinh nhanh cac gia tri bieu thuc sau :
a) 17.91,5+170.0,85 b) 20162-162
c) x(x-10-y(1-x)tai x=2001va y = 2999
2.a là x=0 , x=-1, x=-2
2.b là x=2/3 , x=-5
Tìm x:
a)x(2x-4)-(x-2)(2x+3)
b)x(3x+2)+(x+1)^2-(2x-5)(2x+5)=-12
c)(x-1)(x^2+x+1)-x(x-3)^2=6x^2
d)x^2-x=0
e)(x+2)(x-3)-x-2=0
f)3x^3-27x
Giup mik vs nha
câu a không có về phải=> k làm dc
b)x(3x+2)+(x+1)^2-(2x-5)(2x+5)=-12
<=> 3x^2 +2x +x^2+2x+1 - 4x^2 +25 +12=0
<=> 4x+38=0
=>4x= -38
=>x= -38/4= -19/2
d)x^2-x=0
<=>x(x-1)=0
=>x=0 hoặc x-1=0
=>x=0 hoặc x=1
tính phep nhan x phan x +2-x^3 phan x^3+8 . x^2-2x+4 phần x^2 -4
\(\dfrac{x}{x+2}-\dfrac{x^3}{x^3+8}\cdot\dfrac{x^2-2x+4}{x^2-4}\\ =\dfrac{x}{x+2}-\dfrac{x^3}{\left(x+2\right)\left(x^2-2x+4\right)}\cdot\dfrac{x^2-2x+4}{\left(x-2\right)\left(x+2\right)}\\ =\dfrac{x}{x+2}-\dfrac{x^3}{\left(x+2\right)^2\left(x-2\right)}\\ =\dfrac{x\left(x^2-4\right)-x^3}{\left(x+2\right)^2\left(x-2\right)}=\dfrac{x^3-4x-x^3}{\left(x+2\right)^2\left(x-2\right)}=\dfrac{-4x}{\left(x+2\right)^2\left(x-2\right)}\)
1. a/x(x-3)-x^2=6
b/(x-2)^2 +x(3-x)=5
c/(x-2)(x+1)=x^2=6
d/(x-2)(x+2)-x(x+4)=5
e/(x-3)(x^2+3x+9)-x^3+x=7
f/x^2+3x+2=0
h/(x-1)(x-5)+(3-x)(1+2)=7
l/(x+2)^2-(x-1)^2=0
k/(x+3)(x-3)-(x-1)^2=6
Giup minh nha !! Hoi dai nhung giai dc phan nao thi giai !!
Dung viet ket qua luon nha !! Giai ra ho mk !!
Rut gon phan thuc: (x^(3)-x^(2)-x-2)/(x^(5)-3x^(4)+4x^(3)-5x^(2)+3x-2)
Minh that su da bo tay vs bai tap nay roi! Cac ban hay giup minh nhe! Minh xin cam on!
\(\frac{x^3-x^2-x-2}{x^5-3x^4+4x^3-5x^2+3x-2}\)
\(=\frac{x^3-2x^2+x^2-2x+x-2}{x^5-2x^4-x^4+2x^3+2x^3-4x^2-x^2+2x+x-2}\)
\(=\frac{\left(x^3-2x^2\right)+\left(x^2-2x\right)+\left(x-2\right)}{\left(x^5-2x^4\right)-\left(x^4-2x^3\right)+\left(2x^3-4x^2\right)-\left(x^2-2x\right)+\left(x-2\right)}\)
\(=\frac{x^2\left(x-2\right)+x\left(x-2\right)+\left(x-2\right)}{x^4\left(x-2\right)-x^3\left(x-2\right)+2x^2\left(x-2\right)-x\left(x-2\right)+\left(x-2\right)}\)
\(=\frac{\left(x-2\right)\left(x^2+x+1\right)}{\left(x-2\right)\left(x^4-x^3+2x^2-x+1\right)}=\frac{x^2+x+1}{x^4-x^3+2x^2-x+1}\)