there is only one negative integer value K for which f(x)=K has only one solution for all real X right down the value of K

Which value of c would make he following expression completely factored? 8x+cy

The management of a supermarket wants to adopt a new promotional policy of giving a free gift to every customer who spends more than a certain amount per visit at this supermarket. the expectation of the management is that after this promotional policy is advertised, the expenditures for all customers at this supermarket will be normally distributed with a mean of $95 and a standard deviation of $20. if the management wants to give free gifts to at most 10% of the customers, what should the amount be above which a customer would receive a free gift?

Two years ago a man was six times as old as his daughter. in 18 years he will be twice as old as his daughter. determine their present ages.