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2 years ago

What is -12 = -3y? Can you pls help me

Mathematics

1 answer:

Rashid [163]2 years ago

3 0

Answer:

y = 4

Step-by-step explanation:

-12= -3y

Divide both sides of the equation by

the same term

$\frac{ - 12}{ - 3} = \frac{ - 3y}{ - 3}$

Simplify

Divide the numbers

Cancel terms that are in both the

merator and denominator

Move the variable to the left

y = 4

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Plz answer will give brainliest if correct

pickupchik [31]

Answer:

The answer is A.

Step-by-step explanation:

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3 years ago

Can you please answer this question

tamaranim1 [39]

$3tan^{2} \theta +7sec\theta=3$
First I converted the equation terms into sine and cosine.
$tan^{2}\theta = \frac{sin^{2}\theta}{cos^{2}\theta}$ and $sec\theta= \frac{1}{cos\theta}$
Substitution:
$\frac{3sin^2\theta}{cos^2\theta} + \frac{7}{cos\theta} =3$
Common Denominator Created:
$\frac{3sin^2\theta}{cos^2\theta} + \frac{7cos\theta}{cos^2\theta} =3$
Multiply each term by the LCD:
$3sin^2\theta+7cos\theta=3cos^2\theta$
Substitution: Recall ⇒ $sin^2\theta =1-cos^2\theta$
$3(1-cos^2\theta)+7cos\theta=3cos^2\theta$
Distribute and collect all terms on one side:
$6cos^2\theta-7cos\theta-3=0$
Factor and set each factor equal to 0:
$(2cos\theta-3)(3cos\theta+1)=0$
$2cos\theta-3=0$ ⇒ $theta=cos^{-1} \frac{3}{2}$
$3cos\theta+1=0$ ⇒ $theta=cos^{-1} \frac{-1}{3}$
The 2nd factor provides only possible answer 109.5 degrees

4 0

3 years ago

You want to make 3 pairs of earrings that are in the shape of isosceles triangles. Each earring will have a base of 2 cm. The wi

son4ous [18]

Answer:

The length of each of the other two sides would be 3.1 cm

Step-by-step explanation:

<u><em>The options of the question are</em></u>

A. 3.1 cm

B. 3.2 cm

C. 4.2 cm

D. 6.1 cm

we know that

An isosceles triangle has two equal sides and two equal interior angles

Let

x -----> the length of each of the two equal sides in the isosceles triangle

The perimeter of one isosceles triangle is equal to

$P=2x+2$

Remember that

To maximize the use of the wire, the perimeter of 6 earrings (3 pairs of earrings) must be equal to 50 cm

$6(2x+2)=50$

Solve for x

$12x+12=50$

$12x=50-12$

$12x=38$

$x=\frac{38}{12}=3.16\ cm$

therefore

The length of each of the other two sides would be 3.1 cm

7 0

3 years ago

Suppose that an automobile manufacturer designed a radically new lightweight engine and wants to recommend the grade of gasoline

yawa3891 [41]

Answer:

B) 4.07

Step-by-step explanation:

First we need to calculate the mean of all the data, which is the same as the mean of the means of each grade of gasoline:

Regular BelowRegular Premium SuperPremium

39.31 36.69 38.99 40.04

39.87 40.00 40.02 39.89

39.87 41.01 39.99 39.93

X1⁻=39.68 X2⁻= 39.23 X3⁻= 39.66 X4⁻= 39.95

Xgrand⁻ = (39.68+39.23+39.66+39.95)/4 = 39.63

Next we need to calculate the sum of squares within the group (SSW) and the sum of squares between the groups (SSB), and the respective degrees of freedom):

SSW = [ (39.31-39.68)² + (39.87-39.68)² + (39.87-39.68)² ] + [ (36.69-39.23)² + (40.00-39.23)² + (41.01-39.23)² ] + [ (38.99-39.66)² + (40.02-39.66)² + (39.99-39.66)² ] + [ (40.04-39.95)² + (39.89-39.95)² + (39.93-39.95)² ] = [0.2091] + [10.2129] + [0.6874] + [0.0121] = 11.12

SSW = 11.12

Degrees of freedom in this case is calculated by m(n-1), with m being the number of grades of gasoline (4) and n being the number of trial results for each one (3), so we would have 4(3-1) = 8 degrees of freedom

SSB = [ (39.68-39.63)² + (39.68-39.63)² + (39.68-39.63)²] + [ (39.23-39.63)² + (39.23-39.63)² + (39.23-39.63)² ] + [ (39.66-39.63)² + (39.66-39.63)² + (39.66-39.63)² ] + [ (39.95-39.63)² + (39.95-39.63)² +(39.95-39.63)² ] = [0.0075] + [0.48] + [0.0027] + [0.3072] = 0.7974

SSB = 0.80

For this case, the degrees of freedom are m-1, so we would have 4-1 = 3 degrees of freedom

Now we can establish the hypothesis for the test:

H0: μ1 = μ2 = μ3 = μ4

The null hypothesis states that the means of miles per gallon for each fuel are the same, indicating that the drade of gasoline does not make a difference, therefore our alternative hypothesis will be:

H1: the grade of gasoline does makes a difference

We will use the F statistic to test the hypothesis, which is calculated like follows:

F - statistic = (SSB/m-1) / (SSW/m(n-1)) = (0.80/3) / (11.12/8) = 0.19

We know that the level of significance we are using is α = 0.05, so to find the critical value F we need to look at some table of critical values for the F distribution for the 0.05 significance level (like the attached image). Then we just need to look fot the value that is located in the intersection between the degrees of freedom we have in the numerator (horizontal) and the denominator (vertical) of the statistic (3 and 8). That critical value is:

Fc = 4.07