Y=-2x+5 in standard form

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)

If a and −a are numbers on the number line, which expression must give the distance between them? a) 0 b) a c) |2a| d) |a|

State how many imaginary and real zeros the function has. f(x) = x3 - 20x2 + 123x - 216