X² <span>+ 11x + 7
because 7 is a prime number, this doesn't factor prettily. you'll want to use the quadratic formula; if you aren't familiar with it, i'd either research it or look it up in your textbook, because it's clunky and not easily understood in this format:
(-b </span>± √((b)² - 4ac))/(2a)
in your equation x² + 11x + 7 ... a = 1, b = 11, and c = 7. what you do is you take the coefficients of every term, then plug it into your equation:
(-11 ± √((11)² - 4(1)(7))/(2(1))
not pretty, i know. but, regardless, you can simplify it:
(-11 ± √((11)² - 4(1)(7))/(2(1))
(-11 ± √(121 - 28))/2
(-11 ± √93)/2
and you can't simplify it further. -11 isn't divisible by 2, and 93 doesn't have a perfect square that you can take out from beneath the radical. the ± plus/minus symbol indicates that you have 2 answers, so you can write them out separately:
(x - (-11 - √93)/2) and (x + (-11 - √93)/2)
they look confusing, but those are your two factors. they can be simplified just slightly by changing the signs in the middle due to the -11:
(x + (11 + √93)/2) (x - (11 - √93)/2)
and how these would read, just in case the formatting is too confusing for you: x plus the fraction 11 + root 93 divided by 2. the 11s and root 93s are your numerator, 2s are your denominator.
F(x) represents how many books in total and x represents the number of days
Answer:
a) 0.4164
Step-by-step explanation:
Mean lifespan (μ) = 18.8 days
Standard deviation (σ) = 2 days
For any given lifespan 'X', the z-score is:
For X=12.04 days:
A z-score of -3.38 falls in the 0.036-th percentile of a normal distribution.
For X=18.38 days:
A z-score of -3.38 falls in the 41.68th percentile of a normal distribution.
The probability that a butterfly lives between 12.04 and 18.38 days is
Answer:
BC≈8,38
Step-by-step explanation:
AB=a
BC=c
CA=b
a²+b²=c²
3.3²+7.7²=c²
√70,18=√c²
c≈8,38
