Which expression illustrates the associative property of addition?
. (3+19) - 12 = (3 +12) - 19
O 3 + (19 - 12) = 3 + (19 +12)
(3 +19) - 12 = 3 + (19-12)
O 3+ (19-12) = 3 - (19 +12)

(3 + 19) - 12 = 3 + (19 - 12).

Step-by-step explanation:

The parentheses have migrated to the right  whereas the order of the numbers and operations has stayed the same.

answer: the answer is 127 degrees

b. would be the answer : )

step-by-step explanation:

step 1: add -16x to both sides.

16x−4y+−16x=64+−16x  

−4y=−16x+64

step 2: divide both sides by -4.

−4y /-4 = -16x + 64/-4

answer:   y=4x−16

hope i'm right