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4 years ago

Solve using the quadratic formula. – 2^2 + 3x + 7 = 0

Mathematics

1 answer:

Phantasy [73]4 years ago

3 0

Answer:

x=−1

Step-by-step explanation

Step 1: Simplify both sides of the equation.

−22+3x+7=0

−4+3x+7=0

(3x)+(−4+7)=0(Combine Like Terms)

3x+3=0

Step 2: Subtract 3 from both sides.

3x+3−3=0−3

3x=−3

Step 3: Divide both sides by 3.

−3

x=−1

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A student is 7 years old. If you triple the teachers age and add the student's age the answer is 163. How old is the teacher?

pogonyaev

Answer:

Step-by-step explanation:

We can write this out as an equation. Let's say that the teacher's age is x. Triple the teachers age plus the students age is 163, which can be written out as:

$3x + 7 = 163$

We want to isolate the variable, so subtract 7 from both sides. This gives us:

$3x = 156$

Finally, we divide both sides by 3, giving:

$x=52$

So the teacher is 52 years old.

Hope this helps!

4 0

3 years ago

Read 2 more answers

Which of the following is the correct factorization of the polynomial below?

serg [7]

Answer:

D but see below.

Step-by-step explanation:

It can be factored if you are allowed to use square roots.

(p + 5√5)(p - 5√5)

Usually, you are not allowed to do that. Usually you must be working with whole numbers or rational well behaved fractions.

I think, given the above comment, the answer is D

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3 years ago

43/21 decimal rounded to the nearest hundredth

Step2247 [10]

Answer:

2.05

Step-by-step explanation:

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3 years ago

Which of the following figures has a circumference that is closest to 121 inches?

Eduardwww [97]

Answer:

a circle with a diameter of 19.3 inches

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3 years ago

1. A report from the Secretary of Health and Human Services stated that 70% of single-vehicle traffic fatalities that occur at n

Nuetrik [128]

Using the binomial distribution, it is found that there is a 0.7215 = 72.15% probability that between 10 and 15, inclusive, accidents involved drivers who were intoxicated.

For each fatality, there are only two possible outcomes, either it involved an intoxicated driver, or it did not. The probability of a fatality involving an intoxicated driver is independent of any other fatality, which means that the binomial distribution is used to solve this question.

Binomial probability distribution

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

$C_{n,x} = \frac{n!}{x!(n-x)!}$

The parameters are:

x is the number of successes.
n is the number of trials.
p is the probability of a success on a single trial.

In this problem:

70% of fatalities involve an intoxicated driver, hence $p = 0.7$ .

A sample of 15 fatalities is taken, hence $n = 15$ .

The probability is:

$P(10 \leq X \leq 15) = P(X = 10) + P(X = 11) + P(X = 12) + P(X = 13) + P(X = 14) + P(X = 15)$

Hence

$P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}$

$P(X = 10) = C_{15,10}.(0.7)^{10}.(0.3)^{5} = 0.2061$

$P(X = 11) = C_{15,11}.(0.7)^{11}.(0.3)^{4} = 0.2186$

$P(X = 12) = C_{15,12}.(0.7)^{12}.(0.3)^{3} = 0.1700$

$P(X = 13) = C_{15,13}.(0.7)^{13}.(0.3)^{2} = 0.0916$

$P(X = 14) = C_{15,14}.(0.7)^{14}.(0.3)^{1} = 0.0305$

$P(X = 15) = C_{15,15}.(0.7)^{15}.(0.3)^{0} = 0.0047$

Then:

$P(10 \leq X \leq 15) = P(X = 10) + P(X = 11) + P(X = 12) + P(X = 13) + P(X = 14) + P(X = 15) = 0.2061 + 0.2186 + 0.1700 + 0.0916 + 0.0305 + 0.0047 = 0.7215$

0.7215 = 72.15% probability that between 10 and 15, inclusive, accidents involved drivers who were intoxicated.

A similar problem is given at brainly.com/question/24863377

5 0

3 years ago