All categories

3 years ago

What are the roots of the equation x^2+3x-18=0

1 answer:

8 0

First you open 2 parenthesis with x in each one:

(x )(x )=0

Then, you place the sign of the second term (the x term) in the first parenthesis.

(x+ )(x )=0

Next, you multiply the signs of the x term and the sign of the constant (the third term).
Since + × - = -, then you place a -.

(x+ )(x- )=0

You look at the constant (-18) and the second term (3). What two numbers multiplied give you -18 but subtracted (since the signs inside the parenthesis are opposite) give you 3? Those numbers are 6 and 3.
Since the result of the substraction need to be 3, you place the 6 with the + sign and the 3 with the negative sign (if you think of it, 6-3=3 but 3-6 = -3. That's the reason behind placing the numbers)

(x+6)(x-3)=0

Therefore,

x+6=0 or x-3=0

x=-6 or x=3

Your roots are -6 and 3.

You might be interested in

[(4x + 15) / 5x)] = 1/2

Arada [10]

One way in which to approach this problem would be to treat it as an equation of ratios and to cross multiply:

<span>[(4x + 15) / 5x)] = 1/2 could be written as:

4x + 15 1
----------- = ---
5x 2

Then 8x + 30 = 5x

3x = -30, and so x = -10 (answer). Be certain to check this answer through substitution!

</span>

6 0

3 years ago

the pta is ordering pizza for their next meeting. they plan to order 2 cheese pizzas for every 3 pepperoni pizzas they order. ho

vova2212 [387]

10 cheese pizzas

use simple ratio, 3:2 (3 pepperoni for every 2 cheese)
to make the ratio bigger, we substitute the "3" pepperoni for "15" pepperoni. then take the new amount, 15/3 original, you get 5. then multiply the 2 original cheese pizzas by that 5, and you get 10 cheese pizza's.

hope that helps

5 0

3 years ago

HELPPPPP ME AND ILL GIVE YOU BRAINLIEST

mote1985 [20]

Answer:

s= 60

-------------

Hope this helps

3 0

3 years ago

The term "freshman 15" refers to the claim that college students typically gain 15lbs during freshman year at college. Assume th

Viefleur [7K]

The probability that a randomly selected male college student gains 15 lb or more during their freshman year is 11.6%

<h3>What is Probability ?</h3>

Probability is defined as the likeliness of an event to happen.

Let X be a random variable that shows the term "freshman 15" that claims that students typically gain 15lb during their freshman year at college.

It is given that

X follows is a normal distribution with a mean of 2.1 lb (μ) and a standard deviation (σ) of 10.8 lb.

Population Mean (μ) = 2.1

Population Standard Deviation (σ) = 10.8

We need to compute Pr(X≥15). The corresponding z-value needed to be computed is:

$\rm Z_{lower} = \dfrac{ X_1 -\mu }{\sigma}\\\\Z_{lower} = \dfrac{ 15-2.1 }{10.8}\\\\\\Z_{lower} = 1.19$

Then the probability is given as

$\rm Pr(X \geq 16 ) = Pr (\dfrac{X -21}{10.8} \geq \dfrac{15-21}{10.8})\\\\= Pr (Z \geq \dfrac{15-2.1}{10.8}\\\\= Pr (Z\geq 1.19)\\\\ = 0.1162$

Pr(X≥15)=0.1162. (11.6%)

The probability that a randomly selected male college student gains 15 lb or more during their freshman year is 11.6%

To know more about Probability

brainly.com/question/11234923

#SPJ1

3 0

2 years ago

A sample of 14 cans of Brand I diet soda gave the mean number of calories of 23 per can with a standard deviation of 3 calories.

dsp73

Answer:

ठथठलछंशू फथजलट एक ओज पनि हो र स्वार्थी यसलाई मैले कसरी भुल्न सक्थेँ र त्यहाँको बडेमाको बिल्डिङ भित्र म. म जिन्दगी एक यात्रा तय गर्न गर्ने हो र त्यहाँको बडेमाको बिल्डिङ बनाउनलाई मुख्य समाचार पृष्ठ सभकेँ रिफ्रेश कए देखू। म भने त्यो भने हेर्न

3 0

3 years ago