Idid the first question, but i don't understand the rest of the questions

2. (10,50)(25,20)
    slope = (20 - 50) / (25 - 10) = - 30 / 15 = -2

3. y = mx + b
   slope(m) = -2
   (25,20)...x = 25 and y = 20
   now we sub and find b, the y int
   20 = -2(25) + b
   20 = -50 + b
   20 + 50 = b
   70 = b
   ur equation is : y = -2x + 70

4. it would be a negative association because there is a negative slope. A negative association is when one variable increases, the other one decreases.

5. ?? there both negative

Not sure what the question is but i hope this x = years100 * x