Answer:

Step-by-step explanation:
As given
if n erasers have a weight of 80 grams .
I.e
n erasera = 80 grams.
1 erasers weight .

Now find out the weight of the 50 erasers.

Simplify the above


Answer:
-4
Step-by-step explanation:
The common difference is found by subtracting the second term from a previous term
So...
3-7 would give the common difference = -4
-1-3 would give the common difference= -4
-5-1 would give the common difference= -4
For a function to have a derivative in a point has to be continuous at the point, that is, it has to be defined at that point, other wise the derivative would be meaningless.