[tex] a)\sqrt{ x^{2} +10x+25} + \sqrt{ x^{2} -6x+9} =8 \\ \\
\sqrt{ (x+5)^{2} } + \sqrt{ (x-3)^{2} }=|x+5| +|x-3| \\ \\[tex] \\ x \geq -5 \\ si \\\x \leq 3=\ \textgreater \ x+5+x-3=8=\ \textgreater \ 2x=6=\ \textgreater \ x=3-A\\[/tex][tex]b)\sqrt{ x^{2} +4x+4} + \sqrt{ x^{2} -14x+49} =9\\\\
\sqrt{ (x+2)^{2}} + \sqrt{ (x-7)^{2}}=9\\\\|x+2|+|x-7|=9\\\\x \geq -2 \\ si \\ x \leq 7
=\ \textgreater \ x+2+x-7=9
=\ \textgreater \ 2x=14 =\ \textgreater \ x=7-A
[/tex]
