Need with perfect square! 40 points

to be a perfect square C needs to be a number that can be squared

 and the middle term needs to be able to be multiplied by 2 or -2 of the square of the 3rd term (C)

 so in this case C = 25

 25 can be squared ( square root of 25 is 5)

square root of 25 (5) times 2 = 10 ( 2nd term)

C = 25

y=3x+4

step-by-step explanation:

given the points a(0,4) and b(-4, -8)

eqn of line ab: (y-4)/(x-0)=(-8-4)/(-4-0)

(y-4)/x=-12/-4=3

y=3x+4