if a 40-pound weight stretches the spring 4 inches, ,find the distance that a 45-pound

1. There are two possible answer that have f(1)=13. The trick to narrow it down is by looking at the pattern. Is the increase constant or at an increasing rate?

f(1) = 13

f(n) = f(n-1) + 26 for n >_2

2. Again there are two possible answers. The trick here is seeing that the pattern stays negative and does not undulate from positive to negative. So the multiplier has to be positive.

f(1) = -24

f(n) = 4 .f(n- 1) for n >_2

3. This one undulates so the answer is...

f(1) = 28

f(n) = -4. f(n-1) for n >_2