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3 years ago

The points (-3,9) and (-1,r) lie on line with slop -2.

Mathematics

1 answer:

adell [148]3 years ago

7 0

Answer:

The value of r is 5

Step-by-step explanation:

The question is

Find out the value of r

we know that

The formula to calculate the slope between two points is equal to

$m=\frac{y2-y1}{x2-x1}$

we have the points

(-3,9) and (-1,r)

substitute

$m=\frac{r-9}{-1+3}$

$m=\frac{r-9}{2}$

Remember that

$m=-2$

substitute the value of m

$-2=\frac{r-9}{2}$

Solve for r

Multiply by 2 both sides

$-4=r-9$

Adds 9 both sides

$-4+9=r-9+9$

$5=r$

Rewrite

$r=5$

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Evaluate the expression. 33 + 6( 2 + 36)

Ivenika [448]

Good morning ☕️

Answer:

261

Step-by-step explanation:

Here we can proceed two ways

WAY1 : using the order of operations

33 + 6( 2 + 36) = 33 + 6×(38)

=261

WAY2 : using distributive property

33 + 6( 2 + 36) = 33 + 6×2 + 6×36

= 33 + 12 + 216

=261

4 0

2 years ago

What is the total surface area of the square pyramid below? question above

Wewaii [24]

Answer:

132 m².

Step-by-step explanation:

What's the surface area of each lateral face of this pyramid?

Each lateral face of this pyramid is a triangle, with

a height of 8 meters
on a base 6 meters.

The base of this pyramid is a square. As a result, all four lateral sides are congruent. The area of each of these triangle is thus

$\displaystyle \frac{1}{2}\times \text{Base}\times \text{Height} = \rm \frac{1}{2} \times 6 \times 8 = 24\; m^{2}$ .

The base of this pyramid is a square. The length of a side of this square is 6 meters. The area of the base will be

$\text{Side}^{2} = \rm 6^{2} = 36\; m^{2}$ .

Put the five faces together to get the total surface area of this square pyramid:

$\rm 4\times 24 + 36 = 132\; m^{2}$ .

8 0

3 years ago

18 8 X 12 What is the value of x?

grigory [225]

Using Pythagorean theorem, the answer should be D

8 0

2 years ago

Can someone write the point slope equation

valentinak56 [21]

Since you have the slope, you can start your equation with y= -8/7x +b. To find b, plug the X value for the point you were given in for the X (-8/7•4) you get -32/7 or -4.57. Then you take the given Y value(4) and subtract the number you just found (4-(-4.57)). You get 8.57. That means your equation is Y= -8/7 + 8.57

6 0

3 years ago

True or False: A race car driver tested his car for time from 0 to 60 mph, and in 20 tests obtained an average of 4.85 seconds w

vredina [299]

Answer:

False

Step-by-step explanation:

given that a race car driver tested his car for time from 0 to 60 mph, and in 20 tests obtained an average of 4.85 seconds with a standard deviation of 1.47 seconds.

Sample size n = 20

since population standard deviation is not known, we can use t critical value for finding out the confidence interval

df=19

t critical = 2.045

Margin of error = $2.045*\frac{s}{\sqrt{n} } \\=2.045*\frac{1.47}{\sqrt{20} } \\=0.6722$

conidence interval = Mean±Margin of error

= $(4.85-0.6722, 4.85+0.6722)\\= (4.1778, 5.5222)$

The given confidence interval is (4.52, 5.18)

Hence the statement is false.

5 0

3 years ago