The answer is d because a horizontal line has a slope of zero.
Multiply the first equation by 4 (so that both equations will have 8x terms) and then subtract:
8x-20y = -24
8x +3y = 68
------------
0 -23y = -92
Now divide both sides by -23:
y = 4
Find x by plugging y=4 into either equation:
8x +3(4) = 68
8x = 68 - 12
8x = 56
x = 7
So the answer is ordered pair is (7,4)
There were 200 books sold. so, they need to sell 300 more to have 500 total books sold.
Add subtraction multiplication and division
