If we let X equal the amount correct and Y equal the amount incorrect, then we know the total quantity of points or questions was 70. So X + y = 70. We got two points for everyone that was right, or two X we lost a half a point. Or subtract 1/2 a point for each one we missed and we got a total square of 110. The first thing is that I'm going to take that second equation and multiply it all the way through by two because it's easier to deal with it if we don't have fractions. So four X -, y equal to 20. Now if we look at the top equation, it already has a positive Y. So if I add the two exactly the way they are now, the positive Y and negative Y cancel. So 5X equal to 90, X equal 58. If we know X equal 58, we can find our Y by 58 + y is 70, so Y equal 12. You need to make sure to check and to answer what is asked for because this is a story problem and there are five parts. Define your variable, set up your equations, solve your equations, check and answer what's asked for.