Question

Giải phương trình:

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

b) \(\sqrt{9\left(2x+1\right)^2}=3\)

c) \(2\sqrt{\left(x+1\right)^2}=0\)

d) \(\sqrt{\left(x-1\right)^2}=-1\)

Answer 1

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

\(\Leftrightarrow\left(x+1\right)^2=2^2\)

\(\Leftrightarrow x+1=2\)

\(\Leftrightarrow x=1\)

Vậy ...

b) \(\sqrt{9\left(2x+1\right)^2}=3\)

\(\Leftrightarrow9\left(2x+1\right)^2=3^2\)

\(\Leftrightarrow9\left(4x+1\right)=9\)

\(\Leftrightarrow4x+1=1\)

\(\Leftrightarrow4x=0\)

\(\Leftrightarrow x=0\)

Vậy ...

c) \(\sqrt[2]{}\) là \(\sqrt{ }\) á

\(\sqrt{\left(x+1\right)^2}=0\)

\(\Leftrightarrow\left(x+1\right)^2=0^2\)

\(\Leftrightarrow x+1=0\)

\(\Leftrightarrow x=0-1=-1\)

Vậy ......

d) \(\sqrt{\left(x-1\right)^2}=-1\)

\(\Leftrightarrow\left(x-1\right)^2=\left(-1\right)^2\)

\(\Leftrightarrow x-1=1\)

\(\Leftrightarrow x=1+1=2\)

Vậy ....

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