Initial value 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 35, 35, 35. Both are steady, so there is one rate.

In one step, y moved 35 while x moved 5.

Now divide: 35 ÷ 5 = 7 — that is how far y moves for one x.

The table starts at x = 9, not at 0, so the value there is not written down — step back to it. Going one x backwards takes 7 off y each time, and there are 9 to go.

73 − 63 = 10. So at x = 0 the value would be 10 — at x = 9 the value is 73, and stepping back 9 of them at 7 each gives 10.