\(16x^2-\left(x+1\right)^2=0\)

\(\Leftrightarrow\left(4x+x+1\right)\left(4x-x-1\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}4x+x+1=0\Leftrightarrow5x=-1\Leftrightarrow x=-\dfrac{1}{5}\\4x-x-1=0\Leftrightarrow3x=1\Leftrightarrow x=\dfrac{1}{3}\end{matrix}\right.\)

Vậy: \(S=\left\{-\dfrac{1}{5};\dfrac{1}{3}\right\}\)

1/ \(7x-5=13-5x\)

\(\Leftrightarrow12x=18\)

\(\Leftrightarrow x=\dfrac{3}{2}\)

Vậy: \(S=\left\{\dfrac{3}{2}\right\}\)

==========

2/ \(19+3x=5-18x\)

\(\Leftrightarrow21x=-14\)

\(\Leftrightarrow x=-\dfrac{2}{3}\)

Vậy: \(S=\left\{-\dfrac{2}{3}\right\}\)

==========

3/ \(x^2+2x-4=-12+3x+x^2\)

\(\Leftrightarrow-x=-8\)

\(\Leftrightarrow x=8\)

Vậy: \(S=\left\{8\right\}\)

===========

4/ \(-\left(x+5\right)=3\left(x-5\right)\)

\(\Leftrightarrow-x-5=3x-15\)

\(\Leftrightarrow-4x=-10\)

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

Vậy: \(S=\left\{\dfrac{5}{2}\right\}\)

==========

5/ \(3\left(x+4\right)=\left(-x+4\right)\)

\(\Leftrightarrow3x+12=-x+4\)

\(\Leftrightarrow4x=-8\)

\(\Leftrightarrow x=-2\)

Vậy: \(S=\left\{-2\right\}\)

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