I think for number 3, it is the third option.
Answer:
b = 4
Step-by-step explanation:
5b + 4 = 24
5b = 20
b = 4
One such polynomial might be

Another with the same roots would be
(2x/-5x)+x^2
(x(2)/(x(-5))+x^2
(-2/5)+x^2, the x values cancel in numerator and denominator and simplify to -2/5
The answer is x=4 and y=-4