Respuesta :

Simplify the first to
7a+9=4a+27
subtract 4a from both sides
7a+9-4a=4a+27-4a
3a+9=27
subtract 9 from both sides.
3a+9-9=27-9
3a=18
divide by 3
3a/3=18/3
a=6


2nd. x=1
hope this helps!