I think it will be C.
hope its correct !
and surely you'd know what the roots are
6a+12=2(3a-8)
6a+12=6a-16
-12. -12
6a=6a-4
-6a -6a
0=-4
no solution because the equation is false.
Finding an angle of a triangle
Search the question on the internet and ask if which it is out of them both answers and there you go
