Given:#color(white)("XXXXXXXXXXXXXX")-2x-6=color(white)("x")14+3x#

Add #6# to both sides:#color(white)("XXXXXXX")ul(color(white)("xxxx")+6)=ul(+6color(white)("xxxxxxx"))#

#color(white)("XXXXXXXXXXXXXXXXXX")-2xcolor(white)("xxxx")=20+3x#

Subtract #x# from both sides:#color(white)("XXX")ul(-3xcolor(white)("xxxx"))=ul(color(white)("xxx")-3x)#

#color(white)("XXXXXXXXXXXXXXXXXX")-5xcolor(white)("xxxx")=20#

Divide both sides by #(-5)color(white)("XX")ul(div (-5)color(white)("xx"))=ul(div(-5))#

#color(white)("XXXXXXXXXXXXXXXXXXXX")xcolor(white)("xxx")=-4#