Y intercept is 24. ( y intercept is when x=0 )
It is the sum of the integers from 1-41 minus the sum of the integers from 1-24 divided by 17
the sum of the integers from 1-41 is (42)(45)/2 = 861
the sum of the integers from 1-24 is (24)(25)/2 = 300
(861-300)/17 = 33
The answer is 33
The second one is the function
For this case, we have the following expression:

We simplify the expression:
If we add similar terms, taking into account that different signs are subtracted and the sign of the greater one is placed, we have that 
So, we have to:

Answer:
-3x + x + 5 = -2x + 5
Because 0.09 is ten times as big as 0.009