Greg and Keith are downloading songs to their cellphones. Greg started with 50 songs downloaded and continues to download 2 songs a week. Keith uses the this table to record his number of downloaded songs. At which week will Keith and Greg have downloaded the same number of songs?
A.15 weeks
B. 5 weeks
C. 20 weeks
D. 10 weeks

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?