Please help me with geometry it is due in one hour

Which matrix can be multiplied to the left of a vector matrix to get a new vector matrix ?

Which expression calculates the speed in meters per second of an object that travels a distance of 100 m every 20 seconds

Subscriptions to a popular fashion magazine have gone down by a consistent percentage each year and can be modeled by the function y = 42,000(0.96)t. what does the value 42,000 represent in the function?