Barrett is ordering t-shirts for his school’s student council. Company D charges a $30 design fee plus $6.25 per t-shirt. Company E charges a $12 design fee plus $9.75 per t-shirt. Which inequality can be used to find x, the minimum number of t- shirts that can be ordered so that the total cost with Company D is less than the total cost with Company E?
a. 6.25x + 30 > 9.75x + 12b. 6.25x + 30 < 9.75x + 12c. 6.25 + 30x > 9.75 + 12xd. 6.25 + 30x < 9.75 + 12x

Ariana starts with 100 milligrams of a radioactive substance. the amount of the substance decreases by 20% each week for a number of weeks, w. the expression 100(1−0.2)w finds the amount of radioactive substance remaining after w weeks. which statement about this expression is true? a) it is the difference between the initial amount and the percent decrease. b) it is the difference between the initial amount and the decay factor after w weeks. c) it is the initial amount raised to the decay factor after w weeks. d) it is the product of the initial amount and the decay factor after w weeks.