a: \(3636:\left(12\cdot x-91\right)=36\)

=>\(12x-91=\frac{3636}{36}=101\)

=>12x=91+101=192

=>\(x=\frac{192}{12}=16\)

b: \(446+2\cdot\left(125-x\right)=546\)

=>\(2\left(125-x\right)=546-446=100\)

=>125-x=50

=>x=125-50=75

c: \(\left(x-36\right):18=10+2\)

=>\(\left(x-36\right):18=12\)

=>\(x-36=18\cdot12=216\)

=>x=216+36=252

Ta có: 3636:(12x−91)=36

12x–91=3636:36

12x–91=101

12x=101+91

12x=192

x=192:12

x=16

Vậy x=16

440 + 2. (125 – x) = 546

2. (125 - x)=546 - 440

2. (125 - x)=106

125 - x=106 : 2

125 - x=53

x=125-53

x=72

a)\(x.3^{15}=3^{17}\)

   \(x=3^{17}:3^{15}\)

\(x=3^2=9\)

b) \(5^x=6^x\Leftrightarrow x=1;x=0\)

c) \(x^3=x^6\)

B2 ss

a)\(3^{45}=\left(3^3\right)^{15}=27^{15}\)

   \(4^{30}=\left(4^2\right)^{15}=16^{15}\)

vì 16¹⁵ < 27¹⁵ nên 4³⁰ < 3⁴⁵

b) 

\(818.820=\left(819-1\right)\left(819+1\right)=819^2-1\)

vì 819² > 819² - 1 nên 819² > 818.820

Ta có: \(\left|x-y+1\right|\ge0\forall x,y\)

=>\(2\left|x-y+1\right|\ge0\forall x,y\) (1)

Ta có: \(\left|y-2\right|\ge0\forall y\)

=>\(3\left|y-2\right|\ge0\forall y\) (2)

Từ (1),(2) suy ra \(2\left|x-y+1\right|+3\left|y-2\right|\ge0\forall x,y\)

=>\(-2\left|x-y+1\right|-3\left|y-2\right|\le0\forall x,y\)

=>\(C=-2\left|x-y+1\right|-3\left|y-2\right|-4\le-4\forall x,y\)

Dấu '=' xảy ra khi \(\begin{cases}x-y+1=0\\ y-2=0\end{cases}\Rightarrow\begin{cases}y=2\\ x=y-1=2-1=1\end{cases}\)

_ vô cực

Nhìu thế

Câu a:

7.(\(x-4\)) = \(7^4:7^3\)

7.(\(x-4\) )=7

(\(x-4\) )=7 : 7

(\(x-4\) )=1

\(x\) = 1+4

\(x\) = 5

Vậy \(x=5\)