All categories

3 years ago

Find the x-intercepts for the parabola defined by the equation below. y = 3x2 + 18x + 15

1 answer:

4 0

Using quadratic formula
x = [-18 +-sq root (324 -4 *3*15)] / 2*3
x = [-18 +-sq root (144)]/6
x1 = (-18 + 12) / 6 = -1
x2 = (-18 -12) / 6 = -30/6 = -5

You might be interested in

Which formula is correct in computing 50% of the volume of the shape below?

elixir [45]

Answer:

Step-by-step explanation:

volume of a cylinder: V=πr^2h

so for 1/2 volume we can just multiply by 1/2

V = 1/2 (πr^2h)

plug in values r = 4.6 and h = 12.4

V= 1/2 π (4.6)^2 (12.4)

so the answer is D

8 0

3 years ago

Jaylan makes limeade using 3/4 cup of water for every 1/5 cup of lime juice. Rene's limeade recipe is different. He uses 2/3 cup

oksano4ka [1.4K]

Jaylan: Juice/Water = (3/4)/(1/5) = 15/4

Water/Juice = (2/3)/(1/6)=4/1 or (16/4) in Rene's .

Rene's combination has more water than Jaylan's limeade, which results in a milder lime flavor. Given that Rene's has more water and both have the same amount of lime juice (assume ratio), Rene's limeade has a milder lime taste.

What is combination in math?

Both "COMBIN" and "nCr" here redirect. See Combination (disambiguation) and NCR for further usage (disambiguation).

A combination in mathematics is a choice made from a group of separate elements where the order of the selection is irrelevant (unlike permutations). Three fruits, such as an apple, an orange, and a pear, for instance, can be combined into three different pairs: an apple and a pear, an apple and an orange, or a pear and an orange. A k-combination of a set S is officially defined as a subset of S's k unique members. So, if and only if each combination has the same elements, two combinations are said to be identical.

Learn more about combination brainly.com/question/20211959

#SPJ9

3 0

1 year ago

Tom wants to reach a second floor window on a house that is 20 feet above ground. If he must put the ladder at a 70 degree angle

joja [24]

Picture a right triangle whose hypotenuse is of unknown length. Let's call that length L. The triangle side opposite the 70 degree angle is then 20 feet. I'd suggest you actually draw this triangle.

Then, using the definition of the sine function,

sin 70 deg = opp / hyp = (20 ft) / L. Transforming this equation, L sin 70 deg = 20 ft. Solving for L:

L = (20 ft) / (sin 70 deg) = 21.28 ft

The ladder length must be 21.28 ft.

4 0

3 years ago

A recent article in The Wall Street Journal compared the cost of adopting children from China with that of Russia. For a sample

denpristay [2]

Answer:

We can conclude the mean cost is larger for adopting children from Russia.

Step-by-step explanation:

To answer this question we can perform an hypothesis testing on the differences of the means with the following null and alternative hypothesis:

$H_0: \mu_1\leq\mu_2\\\\H_1: \mu_1>\mu_2$

The significance level we assume is 0.05.

First we calculate the mean standard error:

$MSE=\frac{SSE}{df}=\frac{n_1\sigma_1^2+n_2\sigma_2^2}{(n_1-1)+(n_2-1)} =\frac{16*835^2+18*1545^2}{16-1+18-1} =1,691,314$

The harmonic mean of the sample sizes is:

$n_h=\frac{2}{1/n_1+1/n_2}=\frac{2}{0.0625+0.0556}=\frac{2}{0.1181}=16.94$

Then we can calculate the estimated standard deviation as:

$\sigma=\sqrt{\frac{2MSE}{n_h} } =\sqrt{\frac{2*1691314}{16.94} } =447$

The t-statistic can be calculated as:

$t=\frac{\Delta M-\Delta \mu}{\sigma}=\frac{(11045-12840)-0}{447} =\frac{-1795}{447}= -4.015$

The degrees of freedom are $df=n_1+n_2-2=18+16-2=32$ .

We can look up the P-value in a table or applet. For t=-4.015 and df=32, the P-value is 0.00017.

The P-value is smaller than the significance level, so the effect is significant and the null hyphotesis (China cost is equal or less than in Russia) is rejected.

We can conclude the mean cost is larger for adopting children from Russia.

4 0

3 years ago

For her birthday, Samantha received a gift card, with a value of $200, to a department store. She wants to purchase at least 5 a

Lilit [14]

Answer:

The system of inequalities are;

p + s ≥ 5

22.49s + 34.99p ≤ 200

Where P represents number of dress pants and s represents the number of sweaters

Step-by-step explanation:

Here, we want to write system of inequalities

Let the number of sweaters be s and the number of pants be p

She wants to purchase at least 5 items

When we have at least, it means that it might be greater than or equal to that value

Thus;

p + s ≥ 5

Secondly, at most the amount to be spent is the value on the gift card which is 200

Thus;

we have;

22.49s + 34.99d ≤ 200

5 0

3 years ago