Well, since you have two variables in one equation, you would have to have at least one other equation to solve this problem. Their isn't enough information to solve this alone, sorry :/
To get the volume of an object, one of the oldest techniques is to fill a container with water of which we know the volume (in this case 85mL), and drop the object in. The water will rise and show a new volume (225mL). If we subtract the old volume (85) from the new volume (225), we will get the volume of the object (225 - 85 = 140).
Equation: 21+n=43.23
Process to find n
21+n=43.23
Subtract 21 from both sides
n=22.23
After plugging in X =1 and Y=-3 your answer would be -14
