The answer is b the two equations are equal to each other
(-3, 6) includes all numbers between -3 and 6 but it does not include -3 and 6.
when you put square parentheses you include the number on the edge
so if an anwser includes all numbers between -3 and 6 and the number 6 it's correct to write (-3,6]
+2 crosses the equal sign to become 4y=18-2,as 18-2=16 so you get 4y=16 and finally divide both sides by 4,as 4 goes into 16,4 times,therefore,y=4