a) x(x-8)-x(x+1)=2

    x² -8x -x²-x=2

    -9x=2

    \(x=-\frac{2}{9}\)

b) (x+3)5 - 7(x+9)=0

 5x + 15 -7x -63=0

-2x - 48 =0

-2x=48

x=-24

c)4(x-7)+7(x-2)=11

 4x -28 + 7x -14=11

11x -42=11

11x=11+42

11x=53

x=\(\frac{53}{11}\)

a.\(\left(x-1\right)^2+x\left(4-x\right)=11\)

\(\Leftrightarrow x^2-2x+1+4x-x^2=11\)

\(\Leftrightarrow2x=10\)

\(\Leftrightarrow x=5\)

b. \(x^2-9-2\left(x+3\right)=0\)

\(\Leftrightarrow x^2-9-2x-6=0\)

\(\Leftrightarrow x^2-2x-15=0\)

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

x^2-2x+1+4x-x^2=11

                   2x+1=11

                       x=5

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a) \(15-5\left|x+4\right|=-12-3\)

\(\Leftrightarrow5\left|x+4\right|=30\)

\(\Leftrightarrow\left|x+4\right|=6\)

\(\Leftrightarrow\orbr{\begin{cases}x+4=6\\x+4=-6\end{cases}}\Leftrightarrow\orbr{\begin{cases}x=2\\x=-10\end{cases}}\)

b) \(\left(4x-8\right)\left(7-x\right)=0\Leftrightarrow\orbr{\begin{cases}4x-8=0\\7-x=0\end{cases}}\Leftrightarrow\orbr{\begin{cases}x=2\\x=7\end{cases}}\)

c) \(\left(x^2-36\right)\left(x^2+5\right)=0\Rightarrow\left(x-6\right)\left(x+6\right)=0\)

\(\Leftrightarrow\orbr{\begin{cases}x-6=0\\x+6=0\end{cases}}\Leftrightarrow\orbr{\begin{cases}x=6\\x=-6\end{cases}}\)

d) \(-3\left(x+7\right)-11=2\left(x+5\right)\)

\(\Leftrightarrow-3x-32=2x+10\)

\(\Leftrightarrow5x=-42\Rightarrow x=-\frac{42}{5}\)