a is positive and b is negative from the info that they tell us
a. negative
a has to be negative because of the sign and b is going to be negative, so there is no way that there is going to be a positive if both are negative
b. positive
a is going to be positive because it says it in the beginning sentence it is and two negatives from the equation and b make a positive, so it is two positives
c. negative
b is negative and a is negative from the sign in the equation which make two negatives
