Answer :

4.8y - 6.9 = 3.18 
4.8y= 3.18 + 6.9 (I added 6.9 to both sides)
4.8 y = 10.08 (I added 3.18 by 6.9)
y = 2.1 (I divided 4.8)

Hope this helps!!
the point of this equation is to figure out the value of the y variable. to do this, you'll need to get the y variable by itself on one side of the equation. 

so first you would add 6.9 to 3.18. 
the equation would now look like this: 
4.8y=10.08 


you would then divide 4.8 by 10.08. this is the last step to getting the y varible by itself on one side of the equation and ultimately the value of y! 
the equation now looks like this: 
y=2.1 

y=2.1 is you answer!
Good luck!