Answer:
d=-9
Step-by-step explanation:
you simplify both side of the equation
d/3-9=-12
1/3d+-9=-12
add 9 both sides
1/3d-9+9=-12+9
1/3d=-3
then you multiply 3 both sides
3 x (1/3d)=(3) x(-3)
Hopes this helps :)