Enter your answer and show all the steps that you use to solve this problem in the space provided

Mathematics

1 answer:

VashaNatasha [74]3 years ago

5 0

Answer: x = -4, x = 5

Step-by-step explanation:

You can use the substitution method for this problem.

y = $x^{2}$ + 2x, but y also = 3x +20.

Because of this, you can determine that $x^{2}$ +2x = 3x + 20 because they are both equal to the same thing, y.

Solve the quadratic equation you got from substitution:

$x^{2}$ + 2x = 3x + 20

$x^{2}$ -x = 20

$x^{2}$ -x -20 = 0

You can factor this equation:

(x+4)(x-5) = 0

x = -4, x = 5

You might be interested in

Police response time to an emergency call is the difference between the time the call is first received by the dispatcher and th

blondinia [14]

Answer:

0.7823 = 78.23% probability that the response time is between 3 and 9 minutes.

Step-by-step explanation:

Normal Probability Distribution:

Problems of normal distributions can be solved using the z-score formula.

In a set with mean $\mu$ and standard deviation $\sigma$ , the z-score of a measure X is given by:

$Z = \frac{X - \mu}{\sigma}$

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the p-value, we get the probability that the value of the measure is greater than X.

Normal distribution with a mean of 7.2 minutes and a standard deviation of 2.1 minutes.

This means that $\mu = 7.2, \sigma = 2.1$