Question

Câu 3: Tìm x biết: 

a. \(\sqrt{\left(2x-1\right)^2}\)= x + 1

b. \(\sqrt{x+3}=5\)

c. \(\sqrt{x+2}=\sqrt{7}\)

 

Answer 1

a)2x-1=x+1

x=2

Vậy x=2

Answer 2

b)\(\sqrt{x+3}=\sqrt{25}\)

x+3=5

x=2

Vậy x=2

Answer 3

c)x+2=7

x=5

Vậy x=5

Answer 4

a) ĐKXĐ: \(x\ge-1\)

\(pt\Leftrightarrow\left|2x-1\right|=x+1\)

\(\Leftrightarrow\left[{}\begin{matrix}2x-1=x+1\left(x\ge\dfrac{1}{2}\right)\\2x-1=-x-1\left(-1\le x< \dfrac{1}{2}\right)\end{matrix}\right.\)

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

b) ĐKXĐ: \(x\ge-3\)

\(pt\Leftrightarrow x+3=25\Leftrightarrow x=22\left(tm\right)\)

c) ĐKXĐ: \(x\ge-2\)

\(pt\Leftrightarrow x+2=7\Leftrightarrow x=5\left(tm\right)\)

Answer 5

ơ sao câu này lại ở đây