\(5^x-2-3^2=2^4-\left(2^8x2^4-2^{10}x2^2\right)\)

\(5^x-2-3^2=2^4-\left(2^{8+4}-2^{10+2}\right)\)

\(5^x-2-3^2=2^4-\left(2^{12}-2^{12}\right)\)

\(5^x-2-3^2=2^4-0\)

\(5^x-2-3^2=2^4\)

\(5^x-2-9=16\)

\(5^x-2=16+9\)

\(5^x-2=25\)

\(5^x=25+2\)

\(5^x=27\)

Bởi vì 27 không phân tích được 1 số có số mũ là 2

\(\Rightarrow\) Không tồn tại x

\(5^{x-2}-9=16-\left(256.16-1024.4\right)\)

\(\Rightarrow5^{x-2}-9=16-\left(4096-4096\right)\)

\(\Rightarrow5^{x-2}-9=16-0\)

\(\Rightarrow5^{x-2}-9=16\)

\(\Rightarrow5^{x-2}=25\)

\(\Rightarrow x-2=25:5\)

\(\Rightarrow x-2=3\)

\(\Rightarrow x=5\)

\(5^{x-2}-3^2=2^4-\left(2^8\cdot2^4-2^{10}\cdot2^2\right)\)

\(\Rightarrow5^{x-2}-3^2=2^4-\left(2^{12}-2^{12}\right)\)

\(\Rightarrow5^{x-2}-9=16-0\)

\(\Rightarrow5^{x-2}=16+9\)

\(\Rightarrow5^{x-2}=25\)

\(\Rightarrow5^{x-2}=5^2\)

\(\Rightarrow x-2=2\)

\(\Rightarrow x=2+2\)

\(\Rightarrow x=4\)

Vậy: x=4

\(\dfrac{xy}{2}-x+\dfrac{x^2}{4}=x\left(\dfrac{y}{2}-1+\dfrac{x}{4}\right)\)

`|x-2|=3-x`

`@TH1:x-2 >= 0<=>x >= 2=>|x-2|=x-2`

    `=>x-2=3-x`

`<=>2x=5`

`<=>x=5/2` (t/m)

`@TH2:x-2 < 0<=>x < 2=>|x-2|=2-x`

    `=>2-x=3-x`

`<=>0x=1` (Vô lí)

Vậy `S={5/2}`

\(\left|x-2\right|=3-x\)

\(\Leftrightarrow\left[{}\begin{matrix}x-2=3-x\\x-2=x-3\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x-2-3+x=0\\x-2-x+3=0\end{matrix}\right.\)

\(\Leftrightarrow\left[{}\begin{matrix}2x-5=0\\\left(x-x\right)+\left(-2+3\right)=0\end{matrix}\right.\)

\(\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{5}{2}\\1=0\left(vl\right)\end{matrix}\right.\)

\(=>x=\dfrac{5}{2}\)

 (t/m)

 (Vô lí)

vậy S={5/2}

(x+2)² +x(x-1)<2x²+1
x²+4x+4+x²-x<2x²+1
3x+4<1
x< -1

Uchiha Itachi

a) 5x + 7x + x = 169

12x + x = 169

13x = 169

x = 169 : 13

x = 13

b) x + x + x - 2 = 13

3x - 2 = 13

3x = 13 + 2

3x = 15

x = 15 : 3

x = 5

Bạn cần viết đề bằng công thức toán ( biểu tượng $\sum$ góc trái khung soạn thảo) để được hỗ trợ tốt hơn.

\(3\left(x+2\right)^2-5^2=2.5^2\)

\(\Rightarrow3\left(x+2\right)^2=2.5^2+5^2\)

\(\Rightarrow3\left(x+2\right)^2=5^2\left(2+1\right)\)

\(\Rightarrow3\left(x+2\right)^2=5^2.3\)

\(\Rightarrow\left(x+2\right)^2=5^2\)

\(\Rightarrow\left[{}\begin{matrix}x+2=5\\x+2=-5\end{matrix}\right.\)

\(\Rightarrow\left[{}\begin{matrix}x=3\\x=-7\end{matrix}\right.\) \(\Rightarrow x=3\left(x\inℕ\right)\)

3(x + 2)² - 5² = 2.5²

3(x + 2)² - 25 = 50

3(x + 2)² = 50 + 25

3(x + 2)² = 75

(x + 2)² = 75 : 3

(x + 2)² = 25

x + 2 = 5 hoặc x + 2 = -5

*) x + 2 = 5

x = 5 - 2

x = 3 (nhận)

*) x + 2 = -5

x = -5 - 2

x = -7 (loại)

Vậy x = 3