Question

[✿.｡.:* ☆:**:.Lê Thùy Linh.:**:.☆*.:...]

Cần gấp trc 7h nha:(

Answer 1

[Xyz OLM]

4. a) \(\frac{16}{2^x}=2\Rightarrow2^x=8\Rightarrow2^x=2^3\Rightarrow x=3\)

b) \(3^{x+2}-3^x=24\)

<=> 3^x.3² - 3^x = 24

<=> 3^x.9 - 3^x = 24

<=> 3^x.8 = 24

<=> 3^x = 3

<=> x = 1

Vậy x = 1

Answer 2

[Xyz OLM]

5. a) \(\left|x-\frac{1}{4}\right|=\frac{1}{2}\Rightarrow\orbr{\begin{cases}x-\frac{1}{4}=\frac{1}{2}\\x-\frac{1}{4}=-\frac{1.}{2}\end{cases}}\Rightarrow\orbr{\begin{cases}x=\frac{3}{4}\\x=-\frac{1}{4}\end{cases}}\)

Vậy \(x\in\left\{\frac{3}{4};-\frac{1}{4}\right\}\)

b) \(\left|x\right|-\frac{1}{3}=-\frac{1}{3}\Rightarrow\left|x\right|=0\Rightarrow x=0\)

Vậy x = 0

c) Ta có \(\left|x-\frac{1}{2}\right|\ge0\forall x\)mà - 8 < 0

=> \(x\in\varnothing\)

Vậy  \(x\in\varnothing\)