Answer:
s = - 1 ±
Step-by-step explanation:
Given
s² + 2s - 6 = 0 ( add 6 to both sides )
s² + 2s = 6
To complete the square
add ( half the coefficient of the s- term )² to both sides
s² + 2(1)s + 1 = 6 + 1
(s + 1)² = 7 ( take the square root of both sides )
s + 1 = ± ( subtract 1 from both sides )
s = - 1 ±
Thus
s = - 1 - , s = - 1 +
Answer:
0.0014 = 0.14% probability that Ashley, Bob, Claire, and Daniel will be chosen.
Step-by-step explanation:
A probability is the number of desired outcomes divided by the number of total outcomes.
The order in which the students are chosen is not important, so the combinations formula is used to solve this question.
Combinations formula:
is the number of different combinations of x objects from a set of n elements, given by the following formula.
Desired outcomes:
4 students from a set of 4(Ashley, Bob, Claire, and Daniel). So
Total outcomes:
4 students from a set of 13(number of students in the lottery). So
Probability:
0.0014 = 0.14% probability that Ashley, Bob, Claire, and Daniel will be chosen.