Write the equation of the circle with diameter endpoints of (-2,2) and (2,2)

Can someone factor this fully? my friend and i have two different answers and i would like to know if either of them is right. you in advance. a^2 - b^2 + 25 + 10a

Your friend uses c=50p to find the total cost, c, for the people, p, entering a local amusement park is the cost of admission proportional to the amount of people entering the amusement park? explain.

An 18% discount on a watch saved a shopper $72. find the price of the watch before the discount