Rate of change from a table

Rate of change is how much y moves for each 1 that x moves: the change in y divided by the change in x.

Take both rows of steps. x moves 5, 5, 5 — the same each time — and y moves −25, −25, −25. Both are steady, so there is one rate.

In one step, y moved −25 while x moved 5.

Now divide: −25 ÷ 5 = −5 — that is how far y moves for one x.

The table starts at x = 7, not at 0, so the value there is not written down — step back to it. Going one x backwards adds 5 to y each time, and there are 7 to go.

90 + 35 = 125. So at x = 0 the value would be 125 — at x = 7 the value is 90, and stepping back 7 of them at −5 each gives 125.