Plz, help I need for my work.

Mackenzie needs to determine whether the rectangles are proportional. which process could she use? check all that apply.

The half-life of a certain material is 0.004 second. approximately how much of a 20-gram sample will be left after 0.016 second? a. 5 grams b. 16 grams c. 0.32 gram d. 1.25 grams

What is the 8th term of the geometric sequence with this explicit formula? an= )(n-1)