4 (i literally had to think about this cause i thought it was too easy )
first off, let's convert the mixed fraction to improper fraction and then proceed, let's notice that by PEMDAS or order of operations, the multiplication is done first, and then any sums.
![\stackrel{mixed}{1\frac{7}{8}}\implies \cfrac{1\cdot 8+7}{8}\implies \stackrel{improper}{\cfrac{15}{8}} \\\\[-0.35em] ~\dotfill\\\\ -\cfrac{3}{4}~~ + ~~\cfrac{15}{8} \div \cfrac{1}{2}\implies -\cfrac{3}{4}~~ + ~~\cfrac{15}{8} \cdot \cfrac{2}{1}\implies -\cfrac{3}{4}~~ + ~~\cfrac{15}{4} \\\\\\ \cfrac{-3+15}{4}\implies \cfrac{12}{4}\implies 3](https://tex.z-dn.net/?f=%5Cstackrel%7Bmixed%7D%7B1%5Cfrac%7B7%7D%7B8%7D%7D%5Cimplies%20%5Ccfrac%7B1%5Ccdot%208%2B7%7D%7B8%7D%5Cimplies%20%5Cstackrel%7Bimproper%7D%7B%5Ccfrac%7B15%7D%7B8%7D%7D%20%5C%5C%5C%5C%5B-0.35em%5D%20~%5Cdotfill%5C%5C%5C%5C%20-%5Ccfrac%7B3%7D%7B4%7D~~%20%2B%20~~%5Ccfrac%7B15%7D%7B8%7D%20%5Cdiv%20%5Ccfrac%7B1%7D%7B2%7D%5Cimplies%20-%5Ccfrac%7B3%7D%7B4%7D~~%20%2B%20~~%5Ccfrac%7B15%7D%7B8%7D%20%5Ccdot%20%5Ccfrac%7B2%7D%7B1%7D%5Cimplies%20-%5Ccfrac%7B3%7D%7B4%7D~~%20%2B%20~~%5Ccfrac%7B15%7D%7B4%7D%20%5C%5C%5C%5C%5C%5C%20%5Ccfrac%7B-3%2B15%7D%7B4%7D%5Cimplies%20%5Ccfrac%7B12%7D%7B4%7D%5Cimplies%203)
Answer:
infinite solutions
Step-by-step explanation:
Eliminate parentheses and collect terms:
3x -12 +5 -x = 2x -7
2x -7 = 2x -7
This is true for any value of x. There are an infinite number of solutions.
He should take them out at 9:20.
Hope this helps!