Yes it is. A gallon is 4 quarts, so he has more than enough. He has 2 quarts extra.
If we rewrite it as y=mx+d (which can be taken from here from subtracting ax and c from both sides, then dividing b, resulting in y=(-a/b)(x)-c/b. We can then substitute -a/b for m and -c/b for d), if d=0, then we have m as a constant and as we add a specific number to y (that number being m) every time the x value increases by 1, it therefore forms a straight line. If d is not 0, then we simply add d to every single number - this is still a straight line due to that we still add a specific number to y every time x increases by 1 every single time
Answer:
x=2.125
y=0
C=19.125
Step-by-step explanation:
To solve this problem we can use a graphical method, we start first noticing the restrictions 
and 
, which restricts the solution to be in the positive quadrant. Then we plot the first restriction 
shown in purple, then we can plot the second one 
shown in the second plot in green.
The intersection of all three restrictions is plotted in white on the third plot. The intersection points are also marked.
So restrictions intersect on (0,0), (0,1.7) and (2.215,0). Replacing these coordinates on the objective function we get C=0, C=11.9, and C=19.125 respectively. So The function is maximized at (2.215,0) with C=19.125.
