Well, you can't really determine the price of 1 book, but you can find out the average cost.
280 - 16 = 8x (x = cost of 1 book)
264 = 8x
264/8 = 8x/8
33 = x
So the average cost of one book is 33$( A little expensive if I do say so myself)
Hope this helped!
Answer:
y = -2x -7
Step-by-step explanation:
Parallel lines have the same slope
y = -2x has a slope of -2
The parallel line will have a slope of -2
It goes through a point of (0,-7). This would be the y intercept
y = mx+b
y = -2x -7
Two rational real solutions -8 & +8