SOMEONE HELP PLEASE Explain what the slope of each line below represents. then find the slope and give it's units

Asquare parking lot has 6,400 square meters what is the length in meters

Write the rational number in lowest terms 99/-15

If the endpoints of the diameter of a circle are (8, 6) and (2,0), what is the standard form equation of the circle? a) (x + 5)2 + (y + 3)2 = 18 (x + 5)2 + (y + 3)2 = 3.72 (x - 5)2 + (y - 3)2 = 18 d) (x - 5)2 + (y - 3)2 = 32