Would anyone know what it means to “merge” the functions together while eliminating the variable t?

The difference of three and the reciprocal of a number is equal to the quotient of 20 and the number. find the number.

Aright cylinder has a diameter of 8 m and a height of 6m. what is the volume of the cylinder

At the beginning of a call to the cable company, a message tells customers, "after you finish talking to our customer service representative, you will be asked to take a five-question survey about the level of service you recieved. it would be appreciated if you could stay on the line to answer the survey questions." what type of sampling is the cable company using?