My answer would be 8.. I may not be correct, but I tried. So, I placed the numbers from least to greatest and split it 1’s and 2’s VS 3’s and 4’s. I just added 1 plus 2 plus 2 and a half plus 2 and a half and got 8. I also added (3+3+3)+3 and a half plus 3
An infinite number of solutions means a coincident line...it is the same line 3y = 2x - 9...divide by 3 y = 2/3x - 3...hmm...same line as answer choice b....they are coincident lines and have infinite solutions