Answer:
x² - 9x + 14 by completing the square is (x - 9/2)² - 25/4
Step-by-step explanation:
Given x² - 9x + 14
To rewrite by completing the square, we need to write this in the form (a + b)² or (a - b)² without changing the value of the expression.
(a + b)² = a² + 2ab + b² (equation 1)
(a - b)² = a² - 2ab + b² (equation 2)
x² - 9x + 14 = x² - 2(x)(9/2) + (9/2)² - 25/4 (equation 3)
Comparing (equation 3) with (equation 1) and (equation 2), we can see that it takes the form of (equation 1), though, surplus of 25/4, where a = x, and b = 9/2.
So
x² - 2(x)(9/2) + (9/2)² = x² - 2(x)(9/2) + 81/4 = (x - 9/2)²
Which means
x² - 9x + 14
= x² - 2(x)(9/2) + 81/4 - 25/4
= x² - 2(x)(9/2) + (9/2)² - 25/4
= (x - 9/2)² - 25/4
And the square is completed.
Answer:
4 stations
Step-by-step explanation:
If we need to be at least 98% certain that an enemy plane flying over will be detected by at least one station, we must ensure that there is at most a 2% chance that no radar stations detect the plane.
The probability that a single radar station does not detect the plane is 0.35.
For n radar stations:
Rounding up to the next whole station, at least 4 stations are needed.
Answer: 104
Step-by-step explanation:
