3x-6 this is the answer because it rose 3 and the Y intercept is -6
Apples went up 0.75 a lb
p is the start price so new price is p + 0.75
we buy 3 lbs
3 ( p+ 0.75) = 5.88
now solve
3p + 2.25 = 5.88
-2.25 -2.25
3p = 3.63
/3 /3
p = 1.21 a lb
x=3 is your answer. This is because it only crosses the x-axis and this occurs at positive 3. y=3 on the other hand would be a horizontal line that only touches positive 3 on the y-axis.
Since is addition you do the opposite and subtract 12 from 12 and -5 then 12 cancels out and -5-12=-17