Answer:
70
Step-by-step explanation:
By exterior angle theorem:

It is not differentiable at x=1 since the slope of the tangent line as x -> 1 from the right is 1 while the slope of the tangent line as x->1 from the left is -1
-4j - 1 - 4j + 6 :Combine like terms (-4j and -4j) (-1 and 6)
<em><u>-8j + 5</u></em>