a) \(x-2=-6\)

\(x=-6+2\)

\(x=-4\)

b) \(15-\left(x-7\right)=-21\)

\(x-7=36\)

\(x=43\)

c) \(4.\left(3x-4\right)-2=18\)

\(4\left(3x-4\right)=20\)

\(3x-4=5\)

\(3x=9\)

\(x=3\)

d) \(\left(3x-6\right)+3=32\)

\(3x-6=29\)

\(3x=29+6\)

\(3x=35\)

\(x=\frac{35}{3}\)

e) \(\left(3x-6\right).3=32\)

\(3x-6=\frac{32}{3}\)

\(3x=\frac{32}{3}+6\)

\(3x=\frac{50}{3}\)

\(x=\frac{50}{9}\)

f) \(\left(3x-6\right):3=32\)

\(3x-6=96\)

\(3x=102\)

\(x=34\)

g) \(\left(3x-6\right)-3=32\)

\(3x-6=35\)

\(3x=41\)

\(x=\frac{41}{3}\)

h) \(\left(3x-2^4\right).7^3=2.7^4\)

\(\left(3x-2^4\right)=2.7=14\)

\(\left(3x-16\right)=14\)

\(3x=14+16=30\)

\(x=10\)

i) \(\left|x\right|=\left|-7\right|\)

\(\left|x\right|=7\)

\(\Rightarrow\orbr{\begin{cases}x=7\\x=-7\end{cases}}\)

k) \(\left|x+1\right|=2\)

\(\Rightarrow\orbr{\begin{cases}x+1=2\\x+1=-2\end{cases}\Rightarrow\orbr{\begin{cases}x=1\\x=-3\end{cases}}}\)

l) \(\left|x-2\right|=3\)

\(\Rightarrow\orbr{\begin{cases}x-2=3\\x-2=-3\end{cases}\Rightarrow\orbr{\begin{cases}x=5\\x=-1\end{cases}}}\)

m) \(x+\left|-2\right|=0\)

\(x+2=0\)

\(x=-2\)

o) \(72-3\left|x+1\right|=9\)

\(3\left|x-1\right|=63\)

\(\left|x-1\right|=21\)

\(\Rightarrow\orbr{\begin{cases}x-1=21\\x-1=-21\end{cases}\Rightarrow\orbr{\begin{cases}x=22\\x=-20\end{cases}}}\)

p) Ta có: \(\left|x-1\right|=3\)

\(\Rightarrow\orbr{\begin{cases}x-1=3\\x-1=-3\end{cases}}\)

mà \(x+1< 0\)

\(\Rightarrow x-1=-3\)

\(\Rightarrow x=-2\)

q) \(\left(x-2\right)\left(x+4\right)=0\)

\(\Rightarrow\orbr{\begin{cases}x-2=0\\x+4=0\end{cases}\Rightarrow\orbr{\begin{cases}x=2\\x=-4\end{cases}}}\)

hok tốt!!

c: (3x-2)(x+3)<0

=>x+3>0 và 3x-2<0

=>-3<x<2/3

d: \(\dfrac{x-2}{x-10}>=0\)

=>x-10>0 hoặc x-2<=0

=>x>10 hoặc x<=2

e: \(3x^2+7x+4< 0\)

\(\Leftrightarrow3x^2+3x+4x+4< 0\)

=>(x+1)(3x+4)<0

=>-4/3<x<-1

nik lộn

2^x+1. 2^{2009 =} 2²⁰¹⁰

10 - 2x = 25 - 3x

suy ra |x+3|=1;2

thì x+3= -2;-1;1;2

0 < l x +3 l <3

=lx+3l=1;2

x+3=-2;-1;1;2

giúp mik đi mà, gấp lắm, mik phải đi học ngay r, huhuhu

a: 3x-5>15-x

=>4x>20

hay x>5

b: \(3\left(x-2\right)\left(x+2\right)< 3x^2+x\)

=>3x²+x>3x²-12

=>x>-12

a: 3x-5>15-x

=>3x+x>15+5

=>4x>20

=>x>5

b: \(3\left(x-2\right)\left(x+2\right)<3x^2+x\)

=>\(3\left(x^2-4\right)<3x^2+x\)

=>\(3x^2-12-3x^2-x<0\)

=>-x-12<0

=>x+12>0

=>x>-12

c: \(\left(2x+1\right)^2+3x\left(1-x\right)\le\left(x+2\right)^2\)

=>\(4x^2+4x+1+3x-3x^2\le x^2+4x+4\)

=>\(x^2+7x+1\le x^2+4x+4\)

=>7x+1<=4x+4

=>7x-4x<=4-1

=>3x<=3

=>x<=1

d: \(\frac{5x-20}{3}-\frac{2x^2+x}{2}>\frac{x\left(1-3x\right)}{3}-\frac{5x}{4}\)

=>\(\frac{4\left(5x-20\right)-6\left(2x^2+x\right)}{12}>\frac{4x\left(1-3x\right)-15x}{12}\)

=>\(4\left(5x-20\right)-6\left(2x^2+x\right)>4x\left(1-3x\right)-15x\)

=>\(20x-80-12x^2-6x>4x-12x^2-15x\)

=>14x-80>-11x

=>25x>80

=>\(x>\frac{80}{25}=\frac{16}{5}\)

e: 4-2x<=3x-6

=>-2x-3x<=-6-4

=>-5x<=-10

=>x>=2

f: \(\left(x+4\right)\left(5x-1\right)>5x^2+16x+2\)

=>\(5x^2-x+20x-4>5x^2+16x+2\)

=>19x-4>16x+2

=>3x>6

=>x>2

g: \(x\left(2x-1\right)-8<5-2x\left(1-x\right)\)

=>\(2x^2-x-8<5-2x+2x^2\)

=>-x-8<-2x+5

=>-x+2x<5+8

=>x<13

h: \(\frac{3x-1}{4}-\frac{3\left(x-2\right)}{8}-1>\frac{5-3x}{2}\)

=>\(\frac{2\left(3x-1\right)}{8}-\frac{3\left(x-2\right)}{8}-\frac88>\frac{4\left(5-3x\right)}{8}\)

=>2(3x-1)-3(x-2)-8>4(5-3x)

=>6x-2-3x+6-8>20-12x

=>3x-4>20-12x

=>15x>24

=>\(x>\frac{24}{15}\)

=>x>1,6