The number of seats in the first 12 rows of a high school auditorium form an arithmetic sequence. The first row has 9 seats. The second row has 11 seats.
a. Write a recursive formula to represent the sequence.
b. Write an explicit formula to represent the sequence.
c. How many seats are in the 12th row?

Arley is building a model of a city map. in one part of the city, three roads form a right triangle, which harley draws as triangle abc, with the following measures: m∠b=90° and m∠a=30°. in his scale model, the hypotenuse of triangle abc, ac¯¯¯¯¯¯¯¯, has a length of 817−−√ cm. what is the value of a (the length of bc¯¯¯¯¯¯¯¯)?

Select the number of ways in which a line and a circle can intersect

The measure of angle 0 is 600 degrees