Freddy reads an equal number of pages of a book every week. the graph below shows the number of pages of the book left to read, y, after x weeks:
which equation best models the relationship between x and y?
y = −5x + 40
y = −40x + 280
y = −40x + 200
y = −5x + 200

Wow, the only thing i can think of is that it gives you y and x, so you're basically plugging in the other numbers. So y = 200 and x = 5, and if you were to plug those numbers into each equation they give you, you would come up with 15, 80, 0, and 175. But you're trying to get y to equal 200, so the closest one is c. I'm sorry that's the only thing i can come up with. The rest just aren't close.

Num of plants = (original#ofplants)*(1.6)^t