<span>The standard deviation can be zero if all the data points are the same. Thestandard deviation can be larger than the mean. The range of numbers has to be large for this to occur. One such sample is {0, 0, 1, 15, 20}, where = 7.2 and s 8.6.</span>
20t^2+9t-20 is the answer
Answer:the present age of the father is 45 years
Step-by-step explanation:
Let x represent the present age of the father.
Let y represent the present age of the son.
Let z represent the age of the daughter.
A father is 3 times as old as his son. This means that
x = 3y
his daughter is 3 years younger than the son. It means that
z = y - 3
The sum of their ages 3 years ago was 63. This means that
x - 3 + y - 3 + z - 3 = 63
x + y + z - 9 = 63 - - - - - - - - - - 1
Substituting x = 3y and z = y - 3 into equation 1, it becomes
3y + y + y - 3 - 9 = 63
5y - 12 = 63
5y = 63 + 12 = 75
y = 75/5 = 15
x = 3y = 3 × 15
x = 45
z = y - 3 = 15 - 3
z = 12
F(1) = (1)^3 + 2(1)^2 - 5(1) - 6 = 1 + 2 - 5 - 6 = -8; x = 1 is not a solution to the polynomial.
f(-1) = (-1)^3 + 2(-1)^2 - 5(-1) - 6 = -1 + 2 + 5 - 6 = 0; x = -1 is a solution to polynomial.
From the options, a or c has x = -1, both has x = , so lets check for x = 3
f(3) = (3)^3 + 2(3)^2 - 5(3) - 6 = 27 + 18 - 15 - 6 = 24; x = 3 is not a solution to the polynomial.
Therefore the solutions to the polynomial are x = -3, x = -1, x = 2
Answer:
B.{5}
Step-by-step explanation:
2-8x-42=0
(÷2), we get,
1-4x-21=0
-4x-20=0
-4x=20
x=20÷(-4)
x=(-5)
since the question asks for a positive set, the answer is [x=5]