10-139. Without graphing, determine if the graph of each rule below has zero, one, or two x-intercepts. Show all work.
a.
y = 6x2 + 7x – 20
b.
y = x2 - 8x +16
c.
y = 2x2 + x + 3
d.
y= (2x+1)2

PLEASE SHOW EVERY STEP!!
This is from Core Connections Algebra, problem 10-139

Four airplanes carrying a total of 400 passengersarrive at the detroit airport. the airplanes carry, respectively,50, 80, 110, and 160 passengers.a) one of the 400 passengers is selected uniformly at random.let x denote the number of passengers that were on theairplane carrying the randomly selected passenger. find var(x)for x as given in the problemb) one of the 4 airplane drivers is also selected uniformly atrandom. let y denote the number of passengers on the chosen driver’s airplane. find var(y) for y as given in the problem

Consider circle c with angle acb measuring 3/4 radians.if minor arc ab measures 9 inches, what is the length of the radius of circle c? if necessary, round your answer to the nearest inch.

A(1,1) b(-3,0) c(-4,-1) d(3,-2) drag it to correct position