john has two coupons from lacy's department store. one for $20 off and another for 20% off. John wants to purchase a shirt for $64 . his friend reginald told him to use the $20 off coupon because it is the best deal. Which friend is correct and why?

Ascientist has 50 grams of a radioactive element. the amount of radioactive element remaining after t days can be determined using the equation (1) after two days the scientist receives a second shipment of 50 grams of the same element. the equation used to represent the amount of shipment 2 remaining after t days is 10) - 50 which of the following is an equivalent form of the expression for the amount remaining in shipment 2? what’s the answer?