
Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.


\(a,234-\left(x-56\right)=789\)
\(\Leftrightarrow x-56=234-789\)
\(\Leftrightarrow x-56=-555\)
\(\Leftrightarrow x=\left(-555\right)+56=-499\)
Vậy x = -499
b) \(\frac{x+3}{-5}=\frac{x-15}{4}\)
\(\Leftrightarrow4\left(x+3\right)=-5\left(x-15\right)\)
\(\Leftrightarrow4x+12=-5x+75\)
\(\Leftrightarrow4x+12-\left(-5x\right)=75\)
\(\Leftrightarrow4x-\left(-5x\right)+12=75\)
\(\Leftrightarrow4x+5x=63\)
\(\Leftrightarrow9x=63\)
\(\Leftrightarrow x=7\)
Vậy x = 7
c) \(8\left(x-1\right)-7=2\left(x+2\right)+5\)
\(\Leftrightarrow8x-8-7=2x+4+5\)
\(\Leftrightarrow8x-8-7-2x+4=5\)
\(\Leftrightarrow8x-2x-8-7+4=5\)
\(\Leftrightarrow8x-2x=5-4+7+8\)
\(\Leftrightarrow4x=16\)
\(\Leftrightarrow x=4\)
Vậy x = 4
d) Đặt \(D=\frac{2x+3}{x-1}=\frac{2x-2+5}{x-1}=\frac{2\left(x-1\right)+5}{x-1}=2+\frac{5}{x-1}\)
=> \(5⋮x-1\)
=> \(x-1\inƯ\left(5\right)\)
=> \(x-1\in\left\{\pm1;\pm5\right\}\)
=> \(x\in\left\{2;0;6;-4\right\}\)

e) \(\left(x-3\right)\left(x^2+1\right)=0\)
\(\Rightarrow\left(x-3\right)=0\) ( \(x^2+1>0\forall x\))
\(\Rightarrow x=3\)
đ) \(4.8^2=2^x\)
\(2^2.\left(2^3\right)^2=2^x\)
\(2^2.2^6=2^x\)
\(2^8=2^x\)
\(\Rightarrow x=8\)
d) \(\left|x+3\right|=8\)
\(\Rightarrow\orbr{\begin{cases}x+3=8\\x+3=-8\end{cases}}\Rightarrow\orbr{\begin{cases}x=5\\x=-11\end{cases}}\)
mấy câu trên dễ rồi tự làm em nhé


a) x-12:(-2)=4
=> x-12=-8
=> x=4
b ) 6-|x| = 5
=> /x/=1
=> x=1;-1
c ) 7⋮ ( x-3)
=> (x-3) thuộc Ư(7)
=> x-3=1 => x=4
=> x-3=-1 => x=2
=> x-3=7 => x= 10
=> x-3=-7 => x=-4
d ) 3⋮ ( 2x+1 )
=> (2x+1) thuộc Ư(3)
=> (2X+1)= 1 => x= 0
=> (2x+1)=-1 => x= -1
=> 2x+1= 3 => x= 1
=> 2x+1=-3 => x= -2
a) \(x-12:\left(-2\right)=4\Rightarrow x-\left(-6\right)=4\Rightarrow x=\left(-6\right)+4=-2\)
b) \(6-\left|x\right|=5\Rightarrow\left|x\right|=6-5=1\Rightarrow x=\left\{\pm1\right\}\)
c)\(7⋮x-3\Rightarrow x-3\inƯ\left(7\right)\)
\(Ư\left(7\right)=\left\{\pm1;\pm7\right\}\)
\(x=\left\{4;2;10;-4\right\}\)
d) \(3⋮2x+1\Rightarrow2x+1\inƯ\left(3\right)\)
\(Ư\left(3\right)=\left\{\pm1;\pm3\right\}\)
\(x\in\left\{0;-1;1;-2\right\}\)
(2\(x+4\)) : 4 = 5
2\(x+4\) = 5 x 4
2\(x\) + 4 = 20
2\(x\) = 20 - 4
2\(x\) = 16
\(x=16:2\)
\(x=8\)
Vậy \(x=8\)
(2x + 4) : 4 = 5
2x + 4 = 5 x 4
2x + 4 = 20
2x = 20 - 4
2x = 16
x = 16 : 2
x = 8
Vậy x = 8