Please help ASAP. I really need help on this one
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Answer:
Step-by-step explanation:
Given: 8x² + 10x - 7 = 0
<u>When factoring trinomials of the form ax² + bx + c</u>:
- multiply the leading coefficient and the last term.
- find the product factors that add to give you the coefficient of the middle term.
- rewrite the polynomial with those factors replacing the middle term.
1. Split the middle term:
⇒ 8 × -7 = -56 [multiply the leading coefficient and the last term]
⇒ 14, -4 [find the product factors that add to the middle term's coefficient]
⇒ 8x² + 14x - 4x - 7 = 0 [rewrite with those factors replacing the middle term.]
2. Factor by grouping:
⇒ 8x² + 14x - 4x - 7 = 0 [factor out 2x]
⇒ 2x(4x + 7) - 4x - 7 = 0 [factor out -1 or the negative sign]
⇒ 2x(4x + 7) -1(4x + 7) = 0 [factor out 4x + 7]
⟹ (4x + 7)(2x - 1) = 0
3. Separate into 2 cases:
- 4x + 7 = 0
- 2x - 1 = 0
<u><em>Case 1:</em></u>
⇒ 4x + 7 = 0 [subtract 7 from both sides]
⇒ 4x + 7 - 7 = 0 - 7
⇒ 4x = -7 [divide both sides by 4]
⇒ 4x ÷ 4 = -7 ÷ 4
⟹ x =
<u><em>Case 2:</em></u>
⇒ 2x - 1 = 0 [subtract 1 from both sides]
⇒ 2x - 1 + 1 = 0 + 1
⇒ 2x = 1 [divide both sides by 2]
⇒ 2x ÷ 2 = 1 ÷ 2
⟹ x =
Solutions:
Learn more about quadratic equations here:
The prediction for the number of passwords in which the first character is a vowel is 56 passwords.
<h3>How to find that a given condition can be modelled by binomial distribution?</h3>Binomial distributions consist of n independent Bernoulli trials.
Bernoulli trials are those trials which end up randomly either on success (with probability p) or on failures( with probability 1- p = q (say))
Suppose we have random variable X pertaining to a binomial distribution with parameters n and p, then it is written as
The probability that out of n trials, there'd be x successes is given by
The expected value and variance of X are:
Given that the characters that can be used are numbers 0 through 9 and lowercase letters. Therefore, a total of 36 different characters are available.
Since we need to know the passwords made with vowels, therefore, the probability of a password in which the first character will be a, e, i, o, u is (5/36).
Now as the computer produces 400 passwords, therefore, the predicted value can be written as,
Hence, the prediction for the number of passwords in which the first character is a vowel is 56 passwords.
Learn more about Binomial Distribution:
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