What is the derivative of x^2?

Ineed i been stuck on this question since yesterday

The table shows the number of students who signed up for different after school activities. activity students cooking 9 chess 4 photography 8 robotics 11 select the true statements about the information in the table.

The length of a rectangle plus its width is 24 cm. the area is 143 square cm. what are the length and width of the rectangle?