Algebra-1

To find which ordered pair is on the line represented by y=x+70, where y represents the total number of books and x represents the number of weeks since Serine started buying an additional book each week, we need to substitute each option into the equation and check.

Given equation: y=x+70

Let's check each option:

A. For (9,77): y=9+70=79

This does not match77, so (9,77) is not on the line y=x+70.