\(\Leftrightarrow\left(x-28\right).\left(x+6\right)=\left(x+4\right).\left(x-27\right)\)
\(\Leftrightarrow x^2+6x-28x-168=x^2-27x+4x-108\)
\(\Leftrightarrow x^2-22x-168=x^2-23x-108\)
\(\Leftrightarrow\left(-22x+23x\right)=-108+168\)
\(\Leftrightarrow x=60\)