check the picture below.
[tex] \bf \stackrel{BD}{x+26}+DE=\stackrel{BE}{x+27}\implies DE=(x+27)-(x+26)
\\\\\\
DE=x+27-x-26\implies \boxed{DE=1}
\\\\\\
\stackrel{CD}{x+19}+\stackrel{DE}{1}=12\implies x+20=12\implies \boxed{x=-8}
\\\\\\
\stackrel{BE}{x+27}\implies -8+27\implies 19 [/tex]
