Answer:

Step-by-step explanation:





Keeping all like terms in L.H.S ,



i used polynomial division.. i hope this helps :)
It is the commutative property of addition
2 is the answer because if you subtract 12 to 1 it will be 11 and time by 0 and it will be 0 add by 4 and divide it by 2 and it will be 2.