Oi
Just calculating the differential. Step by step:

If you want to know where the tangent has no slope:
To add any fraction You need to make sure that the denominator of the fractions are same. ( denominator in your sum is 19 )
10/19 + 3/19 ( we have the same denominator )
we can also write this problem like
( 10 + 3 ) / 19 { add the numerators together }
13 / 19
So correct option is B.
hope this helped.. :)
I think it’s -0.75. The x coordinate represents the term number so y would show the pattern which is -3.75, -4.5, -5.25, -6, -6.75, -7.5, -8.25, -9. To get to the next number, each term is being decreased by 0.75. Hope this helps :)
There would be an open circle on positive 12 with the arrow moving to the right.