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3 years ago

HELP! 15 pts!

Mathematics

1 answer:

Aleks04 [339]3 years ago

3 0

Answer: B

Step-by-step explanation:

To solve the system of equations, use substitution.

x+y =24

Subtract x on both sides

y=-x+24

We can now substitute -x+24 in for y in the second equation.

3x+5y=100

3x+5(-x+24)=100

Distribute the 5

3x-5x+120=100

Subtract the 120 on both sides

-2x=-20

Divide by 2 on both sides

x=10

Substitute 10 in for x in the first equation.

x+y=24

10+y=24

Subtract 10 inches on both sides

y=14

So there are 10 3point questions and 14 5 point questions, so choice B

Hope this helped!

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PLEASE HELP ASAP!! ALGEBRA! PICTURE BELOW!

zubka84 [21]

Answer:

(y+2)=3/4(x+6) or (y-4)=3/4(x-2)

Step-by-step explanation:

Point-slope form : (y-y1)=m(x-x1)

slope = m =(y2 - y1)/(x2 -x1)

Point 1 (-6,-2), so x1= - 6, y1= -2

Point 2 (2, 4), so x2 = 2, y2 = 4

m=(4-(-2))/(2-(-6)) = 6/8 = 3/4

Point-slope form : (y-y1)=3/4(x-x1)

We can use any point. If we use point 1 we get

Point-slope form : (y+2)=3/4(x+6).

If we use point 2 we get

(y-4)=3/4(x-2)

5 0

4 years ago

Six times a number x, plus 4 times a number y, equals 14. Negative eight times x minus 4 times y equals -12. What are the number

jekas [21]

Converting this into an equation, we get:
6x+4y=14
-8x-4y=-12

We can solve this by adding the system of equations.

6x+4y=14
+ -8x-4y=-12
-------------------------
-2x=2

Simplifying, we get that x=-1. We can replug this into one of the equations to get y. We'll choose 6x+4y=14

Plugging in -1 for x, we get that:
6(-1)+4y=14
which is
-6+4y=14
which is
4y=20

Simplify this to get that y=5

To check, you can plug in x and y into both equations to make sure that they are true.

6(-1)+4(5)=14
-6+20=14
14=14 which is true

-8(-1)-4(5)=-12
8-20=-12
-12=-12 which is true

x=-1 and y=5

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7 0

4 years ago

Find the area of the head using each persons method. Show your reasoning.

diamong [38]

The area of the hexagonal head using each persons (Andre & Lin) method is;

Total Area using Lin's method = 93.6 ft²

Total Area using Andre's method = 93.6 ft²

A) Lin's Method; From division of polygons , we know that a regular hexagon can be divided into 6 equilateral triangles.

From the image, a side of the hexagon is 6 inches. This means that all sides of each triangle will be also 6 inches.

Formula for area of a triangle = ¹/₂(base x height)

We see a perpendicular distance spanning from one end of the hexagon to the other end passing through the centre of the hexagon. It passes 2 triangles.

Thus, the height of one triangle = 10.4/2 ft = 5.2 ft

Area of one triangle = ¹/₂ × 6 × 5.2 = 15.6 ft²

Thus, Area of hexagon = area of 6 triangles = 6 × 15.6 = 93.6 ft²

B) Andre's method;

Let us first find the area of the rectangle;

Area of rectangle = length × width

Area of rectangle = 10.4 × 6 = 62.4 ft²

For the rectangle, we know three sides now which are;

10.4 ft, 6 ft, 6 ft but we don't know the height and as such we will use heron's formula to get the area of one triangle;

A = √s((s - a)(s - b)(s - c))

where; a,b and c are the 3 sides of the triangle

s = (a + b + c)/2

Thus; s = (10.4 + 6 + 6)/2 = 11.2 ft

Thus;

A = √11.2((11.2 - 10.4)(11.2 - 6)(11.2 - 6))

A = 15.6 ft²

There are 2 triangles and so Area of 2 triangles =2 × 15.6 = 31.2 ft²

Thus;

Total Area = 62.4 ft² + 31.2 ft²

Total Area = 93.6 ft²

Read more at; brainly.com/question/15424654

6 0

2 years ago

G(x) = x2 + 3, what is the change made to g(x) if the parent function is f(x) = x2?

swat32

G(x) x^2 + 3 is obtained by shifting the graph of f(x) = x^2 3 units up.

7 0

3 years ago

A random sample of the correct choice on 400 multiple-choice questions on a variety of AP exams1 shows that B was the most commo

maks197457 [2]

Answer:

a) Null hypothesis: $p\leq 0.2$

Alternative hypothesis: $p > 0.2$

b) $z=\frac{0.225 -0.2}{\sqrt{\frac{0.2(1-0.2)}{400}}}=1.25$

$p_v =P(Z>1.25)=0.106$

Step-by-step explanation:

1) Data given and notation

n=400 represent the random sample taken

X=90 represent the number of questions with B as the correct answer

$\hat p=\frac{90}{400}=0.225$ estimated proportion of arrests that were not prosecuted

$p_o=0.2$ is the value that we want to test, since we assume that each question present 5 options and just one is correct, 1/5 =0.2 if all five options were equally likely

$\alpha$ represent the significance level

z would represent the statistic (variable of interest)

$p_v$ represent the p value (variable of interest)

2) Concepts and formulas to use

We need to conduct a hypothesis in order to test the claim that the true proportion is higher than 0.2.:

Null hypothesis: $p\leq 0.2$

Alternative hypothesis: $p > 0.2$

When we conduct a proportion test we need to use the z statisitc, and the is given by:

$z=\frac{\hat p -p_o}{\sqrt{\frac{p_o (1-p_o)}{n}}}$ (1)

The One-Sample Proportion Test is used to assess whether a population proportion $\hat p$ is significantly different from a hypothesized value $p_o$ .

3) Calculate the statistic

Since we have all the info requires we can replace in formula (1) like this:

$z=\frac{0.225 -0.2}{\sqrt{\frac{0.2(1-0.2)}{400}}}=1.25$

4) Statistical decision

It's important to refresh the p value method or p value approach . "This method is about determining "likely" or "unlikely" by determining the probability assuming the null hypothesis were true of observing a more extreme test statistic in the direction of the alternative hypothesis than the one observed". Or in other words is just a method to have an statistical decision to fail to reject or reject the null hypothesis.

The significance level provided $\alpha$ . The next step would be calculate the p value for this test.

Since is a right tailed test the p value would be:

$p_v =P(Z>1.25)=0.106$

If we compare the p value obtained and the significance level assumed $\alpha=0.05$ we have $p_v>\alpha$ so we can conclude that we have enough evidence to FAIL reject the null hypothesis, and we can said that at 5% of significance the proportion of B correct answers is not significantly higher than 0.2.

8 0

4 years ago