Answer:
x = 2, and 6
x = 2 , 6
Step-by-step explanation:
The quadratic function to analyze is: 
In order to find where the corresponding parabola intercepts the x axis, we set it equal to zero (y = 0):

This equation is easy to solve by factoring. We look for a air of integer numbers whose product equals the constant term "12", and whose combinig renders the coefficient of the middle term of the trinomial "-8".
The two such numbers are "-2" and "-6". We use them to split the middle term, and then solve by factoring by grouping:

For the product of two factors to render zero, we need either one to be a zero.This means that (x-2)=0 (that is x = 2), or (x-6)=0 (that is x = 6).
So, there are two x-intercepts: x= 2, and 6
Given:
1 - 50 written in red marker
51 - 100 written in blue marker
Probability of selecting a number greater than 81; 100 - 81 = 19 possible numbers. 1 draw. 1/19
Probability of selecting a number written in red: 1/50
Probability of selecting a number written in blue: 1/50
Probability of selecting a number that is a multiple of 10. There are 10 instances; 10, 20, 30, 40, 50, 60, 70, 80, 90, 100 ; 1/10