Middle school math All Multiple choice

Question 1
What does the slope represent in this situation?

Every week he saves $40
Every 4weeks he saves $60
Every week he save $20
Every 4 weeks he saves $20

Question 2
What does the vertical intercept (y intercept) represent in this situation?

He has already saved $40
He has already saved $20
He has saved $40 a week
He will save $40 next week

Question 3
Is the slope increasing or decreasing?

The position of a moving particle is given by the position function: f(t)=-9t-t^2-0.2t^3+0.1t^4 0 a. at what time does the particle reverse direction? b. when is the displacement positive? (round one decimal place and answer in interval notation) c. when is the displacement negative? (round one decimal place and answer in interval notation) d. when is the particle’s acceleration positive? (round one decimal place and answer in interval notation) e. when is the particle’s acceleration negative? (round one decimal place and answer in interval notation)