First of all, we know that 5x^2+ ax+7x +5=0 only has one root. That means that b^2 - 4ac=0, and we can use this to find the discriminant, ax + 7x.

Now, if we simplified 5x^2+ ax+7x +5=0, by dividing it all by 5, it would be x^2+(a+7)/5x + 1 = 0.

After, we can plug what we know into the formula, b^2 - 4ac=0. It would be:

(a+7)^2 / 25 - 4 = 0

(a+7)^2 / 25 = 4

(a+7)^2 = 100

Since this is a square root, a+7 can be both negative or positive.

a+7= 10, or a+7 = -10

a=3, or a=-17

The question asks for the sum of a, which is 3 + (-17) = -14

Therefore, the answer is -14.

:) have fun with your rsm problems, assuming you got this from the portal.

7 0

3 years ago

3y-3.5/3y+6=17/25.5. find the value of y. give the scale factor of the polygon

Mekhanik [1.2K]

Hi the answer to your question is

((3y - 3.5) / (3y + 6)) * 25.5 = (17 / 25.5) * 25.5

((3y - 3.5) / (3y + 6)) * 25.5 = 17 (76.5y - 89.25) / (3y + 6) = 17

((76.5y - 89.25) / (3y + 6)) * (3y + 6) = 17 * (3y + 6) 76.5y - 89.25 = 51y + 102 76.5y - 51y = 102 + 89.25

25.5y = 191.25

y = 191.25 / 25.5

3 0

3 years ago

The length of time a person takes to decide which shoes to purchase is normally distributed with a mean of 8.21 minutes and a st

madam [21]

Answer:

4.55% probability that a randomly selected individual will take less than 5 minutes to select a shoe purchase.

Since Z > -2 and Z < 2, this outcome is not considered unusual.

Step-by-step explanation:

Problems of normally distributed samples are solved using the z-score formula.

In a set with mean $\mu$ and standard deviation $\sigma$ , the zscore 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 pvalue, we get the probability that the value of the measure is greater than X.

If $Z \leq 2$ or $Z \geq 2$ , the outcome X is considered to be unusual.