tim x biet |3x+1|>4
Tim x biet: (3/4x+5)-(2/3x-4)-(1/6x+1)=(1/3+4)-(1/3x-3)
\(\left(\dfrac{3x}{4}+5\right)-\left(\dfrac{2x}{3}-4\right)-\left(\dfrac{x}{6}+1\right)=\left(\dfrac{1}{3}+4\right)-\left(\dfrac{1}{3}x-3\right)\)
\(\Leftrightarrow\dfrac{3x}{4}-\dfrac{2x}{3}-\dfrac{x}{6}+5+4-1=\dfrac{13}{3}-\dfrac{1}{3}x+9\)
\(\Leftrightarrow\dfrac{9x-8x-2x}{12}+8=\dfrac{13-x}{3}+\dfrac{27}{3}\)
\(\Leftrightarrow\dfrac{-x}{12}+\dfrac{96}{12}=\dfrac{40-x}{3}\Leftrightarrow\dfrac{96-x}{12}=\dfrac{160-4x}{12}\)
\(\Rightarrow96-160=-4x+x\Leftrightarrow-64=-3x\Leftrightarrow x=\dfrac{64}{3}\)
tim x biet;(2x-1)(3x+1)+(3x-4)(3-2x)=5
ta co (2x-1)(3x+1)+(3x+4)(3-2x)=5
(=)6x2-3x+2x-1+6x-6x2+12-8x=5
(=)-4x+11=5
(=)-4x=-6
(=)x=3/2
(2x-1)(3x+1)+(3x-4)(3-2x)=5
<=> 6x2+2x-3x-1+9x-6x2-12+8x=5
<=> 16x-13=5
<=> 16x = 18
<=> x=9/8
Tim x biet:
(3/4x + 5) - (2/3x - 4) - (1/6x + 1) = (1/3x + 4) - (1/3x - 3)
3/4x + 5-(2/3x-4)-(1/6+1)=(1/3x+4)-(1/3x-3)
=3/4x+5-2/3x-4-1/6x+1=1/3x+4-1/3x-3
=-1/12=7
x=84
Đ/S...
tim x biet /3x+1/+/4-x/=3
nhận xét 3 >0
=> /3x+1/= 3x+1
/4-x/= 4-x
ta có 3x+1 + 4 -x = 3
=> 2x + 5 = 3
=> 2x = -2
=> x= -1
tim x biet
|x+1|+|3x+2|=3x
|x-2|+4|x+1|=x-3
tim x biet |3x+1|>4
|3x+1|>4
=>TH1: 3x+1>4
<=>3x>3
<=>x>1
TH2:3x+1<-4
<=>3x<-5
<=>x< -5/3
tim x biet |3x+1|>4
tim x biet -3x/4.(1/x+2/7)=0
tim x ,y,z biet : 3x-2y/5=3x-1/4=2y+5/7