Answer:
5
Step-by-step explanation:
The check digit is the very last digit on the right, the one by itself
First you turn both fractions into improper fractions, (-23/20-47/20) then yousubtract the numerator(the top of the fraction) -23-47=-70--> -70/20=7/2. Hope i helped;)
Substitute -1 for x. 3(-1)-1=-4.
(B)