a) \(\Leftrightarrow2x+5=3^6\\ \Leftrightarrow2x+5=729\\ \Leftrightarrow x=362\)

b) \(\Leftrightarrow x+55=60\\ \Leftrightarrow x=5\)

c) \(x=\left\{12;24;36;48\right\}\)

c) x ⋮ 12 và x < 60

x ∈ B₍₁₂₎ = { 0 ; 12 ; 24 ; 36 ; 48 ; 60 ;...}

mà x ⋮ 12 và x < 60

nên x ∈ B₍₁₂₎= { 0 ; 12 ; 24 ; 36 ; 48 }

a)19 - (x + 2³)=2⁴- 6

   19 - (x + 2³) = 16 - 6 

    19 - (x + 2³) = 10

     (x + 2³) = 19 - 10

      x + 2³= 9

      x + 2³ = 3³

      ^{x + 2 = 3}

      ^{x= 3-2}

       ^{x= 1}

sửa lại :

a)19 - (x + 2³)=2⁴- 6

   19 - (x + 2³) = 16 - 6 

    19 - (x + 2³) = 10

     (x + 2³) = 19 - 10

      x + 2³= 9

    =>  x + 8= 9             x= 1

      ^{=> x + 8 =-9                     x= -17}

sửa lại b) 4³ + 3² : (x + 1) = 65

\(b,\Rightarrow\left(x+2\right)\left(x+2-x+3\right)=0\\ \Rightarrow5\left(x+2\right)=0\\ \Rightarrow x=-2\\ c,\Rightarrow2x\left(x^2-2x+1\right)=0\\ \Rightarrow2x\left(x-1\right)^2=0\\ \Rightarrow\left[{}\begin{matrix}2x=0\\x-1=0\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=0\\x=1\end{matrix}\right.\\ d,\Rightarrow\left(x-1-2x-1\right)\left(x-1+2x+1\right)=0\\ \Rightarrow3x\left(-x-2\right)=0\\ \Rightarrow-3x\left(x+2\right)=0\\ \Rightarrow\left[{}\begin{matrix}-3x=0\\x+2=0\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=0\\x=-2\end{matrix}\right.\)

a)thiếu dấu

b)(x+2)² -(x+2)(x-3)=0

(x+2)(x+2-x+3)=0

(x+2)5=0

x+2=0

x=-2

c)2x³-4x²+2x=0

2x(x²-2x+1)=0

2x(x-1)²

suy ra 2 trường hợp

x=0

x-1=0=>x=1

d)(x-1)²-(2x+1)²=0

(x-1-2x-1)(x-1+2x+1)=0

(x-2)3x=0

x=0

x=2

a) \(\left(2x-3\right)\left(2x+3\right)=0\)

\(\Rightarrow\left[{}\begin{matrix}x=\dfrac{3}{2}\\x=-\dfrac{3}{2}\end{matrix}\right.\)

b) \(x^2-1=0\Rightarrow\left(x-1\right)\left(x+1\right)=0\)

\(\Rightarrow\left[{}\begin{matrix}x=1\\x=-1\end{matrix}\right.\)

c) \(x^2-9=0\Rightarrow\left(x-3\right)\left(x+3\right)=0\)

\(\Rightarrow\left[{}\begin{matrix}x=3\\x=-3\end{matrix}\right.\)

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

\(\Rightarrow\left[{}\begin{matrix}x=2\\x=-2\end{matrix}\right.\)

2) \(\Rightarrow\left(5x-3\right)\left(5x+3\right)=0\)

\(\Rightarrow\left[{}\begin{matrix}x=\dfrac{3}{5}\\x=-\dfrac{3}{5}\end{matrix}\right.\)

Lời giải:
a. Đề có cả x,y. Bạn xem lại

b. 

PT $\Leftrightarrow 5x(x-3)-2(x-3)=0$

$\Leftrightarrow (x-3)(5x-2)=0$

$\Leftrightarrow x-3=0$ hoặc $5x-2=0$

$\Leftrightarrow x=3$ hoặc $x=\frac{2}{5}$

c.

PT $\Leftrightarrow (7x-2)(x-4)=0$

$\Leftrightarrow 7x-2=0$ hoặc $x-4=0$

$\Leftrightarrow x=\frac{2}{7}$ hoặc $x=4$

d. Đề thiếu.

c) \(\left(34-2x\right)\left(2x-6\right)=0\)

\(\Rightarrow\left[{}\begin{matrix}34-2x=0\\2x-6-0\end{matrix}\right.\)

\(\Rightarrow\left[{}\begin{matrix}2x=34\\2x=6\end{matrix}\right.\)

\(\Rightarrow\left[{}\begin{matrix}x=17\\x=3\end{matrix}\right.\)

d) \(\left(2019-x\right)\left(3x-12\right)=0\)

\(\Rightarrow\left[{}\begin{matrix}2019-x=0\\3x-12=0\end{matrix}\right.\)

\(\Rightarrow\left[{}\begin{matrix}x=2019\\3x=12\end{matrix}\right.\)

\(\Rightarrow\left[{}\begin{matrix}x=2019\\x=4\end{matrix}\right.\)

e) \(57\left(9x-27\right)=0\)

\(\Rightarrow9x-27=0\)

\(\Rightarrow9\left(x-3\right)=0\)

\(\Rightarrow x-3=0\)

\(\Rightarrow x=3\)

f) \(25+\left(15-x\right)=30\)

\(\Rightarrow25+15-x=30\)

\(\Rightarrow40-x=30\)

\(\Rightarrow x=40-30\)

\(\Rightarrow x=10\)

g) \(43-\left(24-x\right)=20\)

\(\Rightarrow43-24+x=20\)

\(\Rightarrow19+x=20\)

\(\Rightarrow x=20-19\)

\(\Rightarrow x=1\)

h) \(2\left(x-5\right)-17=25\)

\(\Rightarrow2\left(x-5\right)=17+25\)

\(\Rightarrow x-5=21\)

\(\Rightarrow x=21+5\)

\(\Rightarrow x=26\)

i) \(3\left(x+7\right)-15=27\)

\(\Rightarrow3\left(x+7\right)=27+15\)

\(\Rightarrow x+7=14\)

\(\Rightarrow x=14-7\)

\(\Rightarrow x=7\)

j) \(15+4\left(x-2\right)=95\)

\(\Rightarrow4\left(x-2\right)=95-15\)

\(\Rightarrow4\left(x-2\right)=80\)

\(\Rightarrow x-2=20\)

\(\Rightarrow x=20+2\)

\(\Rightarrow x=22\)

k) \(20-\left(x+14\right)=5\)

\(\Rightarrow x+14=20-5\)

\(\Rightarrow x+14=15\)

\(\Rightarrow x=15-14\)

\(\Rightarrow x=1\)

l) \(14+3\left(5-x\right)=27\)

\(\Rightarrow3\left(5-x\right)=27-14\)

\(\Rightarrow3\left(5-x\right)=13\)

\(\Rightarrow5-x=\dfrac{13}{3}\)

\(\Rightarrow x=5-\dfrac{13}{3}\)

\(\Rightarrow x=\dfrac{2}{3}\)

a) 

x – 8 + 32 = 68

x – 8 = 68 – 32 

x – 8 = 36

x = 36 + 8

x = 44

b) 

x + 8 + 32 = 68

x + 8 = 68 – 32

x + 8 = 36

x = 36 – 8

x = 28

c) 

98 – x + 34 = 43

98 – x = 43 – 34

98 – x = 9

x = 98 – 9 

x = 89 

d) 

98 + x – 34 = 43

98 + x  = 43 + 34 

98 + x = 77

x = 98 – 77 

x = 21

tick cho mink nhé!

a: =>12x-64=32

=>12x=96

=>x=8

b: =>x-1=5

=>x=6

c: =>2^x*3=96

=>2^x=32

=>x=5