Respuesta :

Aaronwu

Answer:

-41/36       also -1 5/36

Step-by-step explanation:

iiSouL

Answer:

The answer is (-41/36)

Step-by-step explanation:

The LCD of 9 and 12 is 36

9 x 4 = 36

12 x 3 = 36

(-20/36) + (-21/36) = (-41/36)

Leave the simplest form to how your teacher wants it, either as a mixed number or just leave it like that.