\(\left(x.7-7\right)\left(x.12+24\right)=0\)

=> \(\orbr{\begin{cases}x.7-7=0\\x.12+24=0\end{cases}}\)

=> \(\orbr{\begin{cases}7x=7\\12x=-24\end{cases}}\)

=> \(\orbr{\begin{cases}x=1\\x=-2\end{cases}}\)

\(170-\left(4+5x\right)=101\)

=> \(4+5x=170-101\)

=> \(4+5x=69\)

=> \(5x=69-4\)

=> \(5x=65\)

=> \(x=65:5=13\)

(x.7-7).(x.12+24)=0

* x.7-7=0                                  * x.12+24=0

x.7=7                                           x.12=24

   x=7:7                                            x=24:12

   x=1                                                x=2

vạy x=1 hoặc x=2

170-(4+5x)=101

4+5x=170-101

4+5x=69

5x=69-4

5x=65

  x=65:5

  x=13

vậy x=13

250:(2x-4)=145-120

250:(2x+4)=25

2x+4=250:25

2x+4=10

2x=10+4

2x=14

  x=14:2

  x=7

vậy x=7

6.x+3.x-4.x=105

x.(6+3-4)=105

x.(9-4)=105

x.5=105

   x=105:5

   x=21

vậy x=21

1) (x.7 - 7)(x.12 + 24) = 0

(7x - 7)(12x + 24) = 0

7x - 7 = 0 hoặc 12x + 24 = 0

7x = 0 + 7          12x = 0 - 24

7x = 7                 12x = -24

x = 1                    x = -2

Vậy: x = 1 hoặc x = -2

2) 170 - (4 + 5x) = 101

170 - 4 - 5x = 101

-5x + 166 = 101

-5x = -65

x = 13

3) 250 : (2x - 4) = 145 - 120

250 : (2x - 4) = 25

125 = 25(x - 2)

125 : 25 = x - 2

5 = x - 2

5 + 2 = x

7 = x

x = 7

4) 6.x + 3.x - 4.x = 105

5.x = 105

x = 105 : 5

x = 21

a: =>1/x=4

hay x=1/4

b: =>x+7=-10

=>x=-17

c: =>x²=36

=>x=6 hoặc x=-6

d: =>(x-3)²=16

=>x-3=4 hoặc x-3=-4

=>x=7 hoặc x=-1

\(a,\dfrac{1}{-x}=-4\\ \Rightarrow\left(-x\right)\left(-4\right)=1\\ \Rightarrow4x=1\\ \Rightarrow x=\dfrac{1}{4}\\ b,\dfrac{x+7}{15}=\dfrac{-24}{36}\\ \Rightarrow\dfrac{x+7}{15}=\dfrac{-2}{3}\\ \Rightarrow3\left(x+7\right)=-2.15\\ \Rightarrow3x+21=-30\\ \Rightarrow3x=-51\\ \Rightarrow x=-17\)

\(c,\dfrac{x}{-3}=\dfrac{-12}{x}\\ \Rightarrow x.x=\left(-3\right)\left(-12\right)\\ \Rightarrow x^2=36\\ \Rightarrow x=\pm6\)

\(d,\dfrac{-2}{x-3}=\dfrac{x-3}{-8}\\ \Rightarrow\left(x-3\right)\left(x-3\right)=\left(-2\right)\left(-8\right)\\ \Rightarrow\left(x-3\right)^2=16\\ \Rightarrow\left[{}\begin{matrix}x-3=4\\x-3=-4\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}x=7\\x=-1\end{matrix}\right.\)

a.\(\Leftrightarrow4x=1\Leftrightarrow x=\dfrac{1}{4}\)

b.\(\Leftrightarrow\left(x+7\right).36=-360\Leftrightarrow x+7=-10\Rightarrow x=-17\)

c.\(x^2=36\Leftrightarrow x=6;-6\)

d.\(-2.-8=\left(x-3\right)\left(x-3\right)\Leftrightarrow16=x^2-6x+9\Leftrightarrow x^2-6x-7=0\Rightarrow x=7;-1\)

a: =>7x=42

hay x=6

b: =>5x=35

hay x=7

c: =>x-14=16

hay x=30

d: =>36-4x=4

=>4x=32

hay x=8

e: =>x-12=144

hay x=156

f: =>3x-16=14

hay x=10

g: =>x+33=45

hay x=12

h: =>(x+9):2=39

=>x+9=78

hay x=69

a: =>7x=42

hay x=6

b: =>5x=35

hay x=7

c: =>x-14=16

hay x=30

d: =>36-4x=4

=>4x=32

a)\(\dfrac{x}{60}=-\dfrac{3}{4}\)

\(\Rightarrow x\cdot4=60\cdot\left(-3\right)\)

   \(x\cdot4=-180\)

  x=45

b)\(\dfrac{2}{5}=\dfrac{12}{x}\)

   \(\Rightarrow2x=5\cdot12\)

      \(2x=60\)

       x=30

c)\(x-\dfrac{5}{7}=\dfrac{6}{21}\)

      \(x=\dfrac{2}{7}+\dfrac{5}{7}\)

      x=1

d)\(x+\dfrac{7}{8}=\dfrac{63}{24}\)

     \(x=\dfrac{21}{8}-\dfrac{7}{8}\)

     \(\dfrac{14}{8}\)

a)\(\dfrac{x}{60}=\dfrac{-3}{4}\Rightarrow x=\dfrac{-3.60}{4}=-45\)

b)\(\dfrac{2}{5}=\dfrac{12}{x}\Rightarrow x=\dfrac{5.12}{2}=30\)

a) \(58+7x=100\)

\(=>7x=100-58\)

\(=>7x=42\)

\(=>x=42:7\)

\(=>x=6\)

b) \(3x-7=28\)

\(=>3x=28+7\)

\(=>3x=35\)

\(=>x=35:3\)

\(=>x=\dfrac{35}{3}\)

c) \(x-56:4=16\)

\(=>x-14=16\)

\(=>x=16+14\)

\(=>x=30\)

d) \(101+\left(36-4x\right)=105\)

\(=>36-4x=105-101\)

\(=>36-4x=4\)

\(=>4x=36-4\)

\(=>4x=32\)

\(=>x=32:4\)

\(=>x=8\)

e) \(\left(x-12\right):12=12\)

\(=>x-12=12.12\)

\(=>x-12=144\)

\(=>x=144-12\)

\(=>x=132\)

f) \(\left(3x-2^4\right).7^3=2.7^4\)

\(=>3x-2^4=2.7^4:7^3\)

\(=>3x-16=2.7=14\)

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

\(=>3x=30\)

\(=>x=30:3\)

\(=>x=10\)

i) \(\left(10+2x\right).4^{2011}=4^{2013}\)

\(=>10+2x=4^{2013}:4^{2011}\)

\(=>10+2x=4^2=16\)

\(=>2x=16-10\)

\(=>2x=6\)

\(=>x=6:2\)

\(=>x=3\)

\(#WendyDang\)