I need help and I need to turning it in 10 mins

Complete the standard form of the equation that represents the quadratic relationship displayed above, where a, b, and c are rational numbers.

International calls require the use of a country code. many country codes a 3-digit numbers. country codes do not begin with a 0 or 1. there are no restrictions on the second and third digits. how many different 3-digit country codes are possible?

An arc subtends a central angle measuring 7pi/4 radians what fraction of the circumference is this arc?