Simplify both sides by combing like terms:
#color(red)(7x)+color(green)(6color(red)(-x)= color(green)(6)+color(red)(5x) color(green)(-10)#
#color(red)(6x)+color(green)(6)= color(green)(-4)+color(red)(5x)#
Subtract #6# from both sides:
#color(red)(6x)+cancel(color(green)(6-6))= color(green)(-4-6)+color(red)(5x)#
#color(red)(6x)= color(green)(-10)+color(red)(5x)#
Subtract #5x# from both sides:
#color(red)(6x-5x)= color(green)(-10)+cancel(color(red)(5x-5x))#
#color(red)(x)= color(green)(-10)#
We can check our answer by substituting #-10# for #x# back into the original problem:
#7(-10)+6-(-10)=6+5(-10)-10#
#-70+6+10=6-50-10#
#-64+10=-44-10#
#-54=-54#
Indeed, our answer is correct!