Giải bất pt a.(2x-1)/3 < (x+6)/2
b.(5(x-1))/6 -1> (2(x+1)/3
giải cá bất pt sau :
a, 3*(x-5)*(x+5)<x*(3x-2)+7
b,5/3-(2x-2/4)>=x-(4x-3/6)
c,(2x-1/3)>(4x+3/5)
\(\frac{5}{3}-\left(2x-\frac{2}{4}\right)\ge x-\left(4x-\frac{3}{6}\right)\)
\(\Leftrightarrow\frac{5}{3}-2x+\frac{1}{2}\ge x-4x+\frac{1}{2}\)
\(\Leftrightarrow x\ge-\frac{5}{3}\)
Ý c cx vậy nha ! Chuyển vế rồi thu gọn lại
Bài 1:
a) Giải PT sau: \(\dfrac{x+1}{x-2}-\dfrac{5}{x+2}=\dfrac{12}{x^2-4}+1\)
b) Giải PT sau: |2x+6|-x=3
a) ĐKXĐ: \(x\notin\left\{2;-2\right\}\)
Ta có: \(\dfrac{x+1}{x-2}-\dfrac{5}{x+2}=\dfrac{12}{x^2-4}+1\)
\(\Leftrightarrow\dfrac{\left(x+1\right)\left(x+2\right)}{\left(x-2\right)\left(x+2\right)}-\dfrac{5\left(x-2\right)}{\left(x+2\right)\left(x-2\right)}=\dfrac{12}{\left(x-2\right)\left(x+2\right)}+\dfrac{x^2-4}{\left(x-2\right)\left(x+2\right)}\)
Suy ra: \(x^2+3x+2-5x+10=12+x^2-4\)
\(\Leftrightarrow x^2-2x+12-8-x^2=0\)
\(\Leftrightarrow-2x+4=0\)
\(\Leftrightarrow-2x=-4\)
hay x=2(loại)
Vậy: \(S=\varnothing\)
b) Ta có: \(\left|2x+6\right|-x=3\)
\(\Leftrightarrow\left|2x+6\right|=x+3\)
\(\Leftrightarrow\left[{}\begin{matrix}2x+6=x+3\left(x\ge-3\right)\\-2x-6=x+3\left(x< -3\right)\end{matrix}\right.\)
\(\Leftrightarrow\left[{}\begin{matrix}2x-x=3-6\\-2x-x=3+6\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=-3\left(nhận\right)\\x=-3\left(loại\right)\end{matrix}\right.\)
Vậy: S={-3}
Bài 1: giải pt
a, \(\frac{4}{x-2}\)+ \(\frac{1}{x+3}\)=0
Bài2 giải bất pt và biểu diễn trên truc số
a, 3x(2x+1)+4<2x(3x-1)-6 b, (2x-3)\(^2\)<(2x+5)(2x-5)
giúp mk nha
mk chỉ giải đc có bài 1 thui nha bn
\(\frac{4}{x-2}+\frac{1}{x+3}=0\)
ĐKXĐ: x ≠ 2 và x ≠ -3
QĐKM:
⇔(x+3)4 + (x-2)1 = 0
⇔4x + 12 + x - 2 = 0
⇔4x + x = -12 + 2
⇔5x = -10
⇔x= -2
S={-2}
giải hệ pt (đặt ẩn phụ )
a) x+2/x+1 + 2/y-2 =6
5/x+1 -1/y-2 =3
b) 2/2x-y +3/x-2y =1/2
2/2x-y -1/x-2y =1/18
c) 2|x-6| +3|y+1| =5
5|x-6| -4|y+1| =1
d) |x| +|y-3| =1
y - |x| =3
a: \(\Leftrightarrow\left\{{}\begin{matrix}\dfrac{x+1+1}{x+1}+\dfrac{2}{y-2}=6\\\dfrac{5}{x+1}-\dfrac{1}{y-2}=3\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}\dfrac{1}{x+1}+\dfrac{2}{y-2}=5\\\dfrac{5}{x+1}-\dfrac{1}{y-2}=3\end{matrix}\right.\)
=>x+1=1 và y-2=1/2
=>x=0 và y=5/2
b: \(\Leftrightarrow\left\{{}\begin{matrix}\dfrac{4}{x-2y}=\dfrac{1}{2}-\dfrac{1}{18}=\dfrac{9}{18}-\dfrac{1}{18}=\dfrac{8}{18}=\dfrac{4}{9}\\\dfrac{2}{2x-y}=\dfrac{1}{18}+\dfrac{1}{x-2y}\end{matrix}\right.\)
=>x-2y=9 và 2/2x-y=1/18+1/9=1/18+2/18=3/18=1/6
=>x-2y=9 và 2x-y=12
=>x=5; y=-2
c: \(\Leftrightarrow\left\{{}\begin{matrix}10\left|x-6\right|+15\left|y+1\right|=25\\10\left|x-6\right|-8\left|y+1\right|=2\end{matrix}\right.\Leftrightarrow\left\{{}\begin{matrix}23\left|y+1\right|=23\\\left|x-6\right|=1\end{matrix}\right.\)
=>|x-6|=1 và |y+1|=1
=>\(\left\{{}\begin{matrix}x\in\left\{7;5\right\}\\y\in\left\{0;-2\right\}\end{matrix}\right.\)
giải pt và bất pt sau:
a.5|2x-1|-3=7
b.(2x+3)(x-2)-x^2+4=0
c. 2x-3/2<1-3x/-5
a, \(5\left|2x-1\right|-3=7\Leftrightarrow5\left|2x-1\right|=10\Leftrightarrow\left|2x-1\right|=2\)
TH1 : \(2x-1=2\Leftrightarrow x=\frac{3}{2}\)
TH2 : \(2x-1=-2\Leftrightarrow x=-\frac{1}{2}\)
b, \(\left(2x+3\right)\left(x-2\right)-x^2+4=0\Leftrightarrow\left(2x+3\right)\left(x-2\right)-\left(x-2\right)\left(x+2\right)=0\)
\(\Leftrightarrow\left(x-2\right)\left(2x+3-x-2\right)=0\Leftrightarrow\left(x-2\right)\left(x+1\right)=0\Leftrightarrow x=-1;x=2\)
c, \(\frac{2x-3}{2}< \frac{1-3x}{-5}\Leftrightarrow\frac{2x-3}{2}+\frac{1-3x}{5}< 0\)
\(\Leftrightarrow\frac{10x-15+2-6x}{10}< 0\Rightarrow4x-13< 0\Leftrightarrow x< \frac{13}{4}\)
`1)` Giải các pt `a)(x+2)/(x-3)+x/(x+2)=(x^{2}+6)/(x^{2}-x-6)` `b)(x+1)^{2}+|x-1|=x^{2}+4` `2)` Giải bất phương trình sau và biểu diễn tập nghiệm trên trục số `1-(x-1)/3<(x+3)/3-(x-2)/2`
1.\(\dfrac{x+2}{x-3}+\dfrac{x}{x+2}=\dfrac{x^2+6}{x^2-x-6}\)
\(\Leftrightarrow\dfrac{x+2}{x-3}+\dfrac{x}{x+2}=\dfrac{x^2+6}{\left(x+2\right)\left(x-3\right)}\)
\(ĐK:x\ne3;-2\)
\(\Leftrightarrow\dfrac{\left(x+2\right)\left(x+2\right)+x\left(x-3\right)}{\left(x+2\right)\left(x-3\right)}=\dfrac{x^2+6}{\left(x+2\right)\left(x-3\right)}\)
\(\Leftrightarrow\left(x+2\right)\left(x+2\right)+x\left(x-3\right)=x^2+6\)
\(\Leftrightarrow x^2+4x+4+x^2-3x-x^2-6=0\)
\(\Leftrightarrow x^2+x-2=0\)
\(\Leftrightarrow\left(x^2-x\right)+\left(2x-2\right)=0\)
\(\Leftrightarrow x\left(x-1\right)+2\left(x-1\right)=0\)
\(\Leftrightarrow\left(x-1\right)\left(x+2\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x=1\left(tm\right)\\x=-2\left(ktm\right)\end{matrix}\right.\)
Vậy \(S=\left\{1\right\}\)
b.\(\left(x+1\right)^2+\left|x-1\right|=x^2+4\)
\(\Leftrightarrow\) \(\left(x+1\right)^2+x-1=x^2+4\) hoặc \(\left(x+1\right)^2+1-x=x^2+4\)
Xét \(\left(x+1\right)^2+x-1=x^2+4\)
\(\Leftrightarrow x^2+2x+1+x-1-x^2-4=0\)
\(\Leftrightarrow3x-4=0\)
\(\Leftrightarrow x=\dfrac{4}{3}\)
Xét \(\left(x+1\right)^2+1-x=x^2+4\)
\(\Leftrightarrow x^2+2x+1+1-x-x^2-4=0\)
\(\Leftrightarrow x-2=0\)
\(\Leftrightarrow x=2\)
Vậy \(S=\left\{\dfrac{4}{3};2\right\}\)
2.\(1-\dfrac{x-1}{3}< \dfrac{x+3}{3}-\dfrac{x-2}{2}\)
\(\Leftrightarrow\dfrac{6-2\left(x-1\right)}{6}< \dfrac{2\left(x+3\right)-3\left(x-2\right)}{6}\)
\(\Leftrightarrow6-2\left(x-1\right)< 2\left(x+3\right)-3\left(x-2\right)\)
\(\Leftrightarrow6-2x+2< 2x+6-3x+6\)
\(\Leftrightarrow-x< 4\)
\(\Leftrightarrow x>4\)
Vậy \(S=\left\{x|x>4\right\}\)
giải pt sau:a,x.(x-3)=(2-x).(x-3)
b,x-1/2+x-1/3+x-1/2016=0
c,2x/3+2x-1/6=4
d,7+2x=4.(5-x)
e,x+2/x-2-1/x=2/x.(x-2)
Giải bất phương trình
a) -x^2+6x-5 < (x-5)(x+6)
b) (2x-1)/5 + 1 - 2x/3 >= 3(x+1)/2 - 7/10