then put y values and x values in in each for every set.
for example
in set 1:
y = 10 - 3x
13 = 10 - 3(-1)
13 = 13 .........cancels out to be 0 as all the other does the same.
<u><em>For every set the answer at the end is coming 0 whereas it should only be above or less than 0 as he needs more 2 dollar to buy another tacos.</em></u>
