If 1/5x = 21/5 then what is x

What is the greatest number of parts of a circle that can be formed by cutting the circle with 7 straight cuts? (note: the parts do not have to be equal in size)

In 2009, there were 1570 bears in a wildlife refuge. in 2010, the population had increased to approximately 1884 bears. if this trend continues and the bear population is increasing exponentially, how many bears will there be in 2018?

Asquare and an equilateral triangle have the same perimeter. each side the triangle is 4 inches longer than each side of the square. what is the perimeter of the square