Answer:
-10,10
Step-by-step explanation:
The given quadratic equation is
The discriminant of this equation is given by;
where a=k, b=20, c=k
For rational solutions, the discriminant must be zero.
Simplify to get:
This implies that:
Take square root to get:
Answer:
a. 720
b. 0.3
Step-by-step explanation:
a.
Three balls are selected at random without replacement.
First ball can be selected in 10 ways
Second ball can be selected in 9 ways
Third ball can be selected in 8 ways
Thus, there are 10×9×8 =720 different ways of selecting three balls.
b.
There are three cases that satisfy this condition
Each probabilities are:
Thus, one of the balls selected is the number 5 is then