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3 years ago

Please solve, -8-2(7r+1)=-94

Mathematics

2 answers:

o-na [289]3 years ago

7 0

-8-14r-2=-94
-10-14r=-94
-14r=-84
r=6

skelet666 [1.2K]3 years ago

4 0

Answer:

r = 6

Step-by-step explanation:

Hello!

-8 - 2(7r + 1) = -94

Add 8 to both sides

-2(7r + 1) = -86

Divide both sides by -2

7r + 1 = 43

Subtract 1 from both sides

7r = 42

Divide both sides by 7

r = 6

Hope this Helps

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Evelyn brought 3 railroad ties to form the sides for a triangular flower bed. two of the railroad ties were 9 feet long and one

vagabundo [1.1K]

To be a triangle, any two of the side lengths added together must be greater than the third length.

9+15 > 9

9+9 > 15

Therefore, yes, the design can be made.

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3 years ago

Bhaskar went for hiking with scouts’ team and there the scouts were given a task to build tents with the help of bamboos, ropes

dimulka [17.4K]

The triangles on Bhaskar's tent are similar triangles.

The length of IJ is 4.5 m
The applicable theorem is the mid-point theorem
The appropriate formula for area is the Heron's formula
The ratio of ABC to DEF is 1 : 9

(a) The length of IJ

The given parameter are:

$\mathbf{EF = 9m}$

I and J are at the midpoint of DE and DF

The above highlight means that

$\mathbf{IJ= \frac 12 \times EF}$ --- midpoint theorem

Substitute 9 for EF

$\mathbf{IJ= \frac 12 \times 9m}$

$\mathbf{IJ= 4.5\ m}$

(b) The property used to find GH and IJ

In (a), the midpoint theorem is used to calculate IJ

GH and IJ are corresponding sides of similar triangles,

So the midpoint theorem can also be used to calculate the length of GH

(c) The area of the triangle

For the given triangles, the lengths of the sides are known.

When side lengths are known, the formula to use for finding the triangle's area is the Heron's formula.

The Heron's formula is:

$\mathbf{Area = \sqrt{s \times (s -a) \times (s - b) \times (s - c)}}$

Where:

$\mathbf{s = a + b + c}\\\mathbf{a,b,c \to sides\ of\ the\ triangle}$

(d): The ratio of the areas:

For the small triangle, we have:

$\mathbf{a= 3.8,\ b = 4,\ c = 3}$

So, we have:

$\mathbf{s = 3.8 + 4 + 3 = 10.8}$

So, the area is:

$\mathbf{Area = \sqrt{s \times (s -a) \times (s - b) \times (s - c)}}$

$\mathbf{A_{small} = \sqrt{10.8 \times (10.8 -3.8) \times (10.8 - 4) \times (10.8 - 3)}}$

$\mathbf{A_{small} = \sqrt{4009.824}}$

For the big triangle, we have:

$\mathbf{a= 11.4,\ b = 12,\ c = 9}$

So, we have:

$\mathbf{s = 11.4 + 12 + 9 = 32.4}$

So, the area is:

$\mathbf{Area = \sqrt{s \times (s -a) \times (s - b) \times (s - c)}}$

$\mathbf{A_{big} = \sqrt{32.4 \times (32.4 -11.4) \times (32.4 - 12) \times (32.4 - 9)}}$

$\mathbf{A_{big} = \sqrt{324795.744}}$

The ratio of the small triangle to the big triangle is:

$\mathbf{Ratio = A_{small} : A_{big}}$

$\mathbf{Ratio = \sqrt{4009.824}:\sqrt{324795.744}}$

Divide by 4009.824

$\mathbf{Ratio = \sqrt{1}:\sqrt{81}}$

Take square roots

$\mathbf{Ratio = 1 : 9}$

Hence, the ratio of ABC to DEF is 1 : 9

Read more about similar triangles at:

brainly.com/question/24874611

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3 years ago

14 over 15 divided by 28

Tanzania [10]

Answer:

1/30 or .00119 (Same answer, just in decimal form)

Step-by-step explanation:

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3 years ago

A standardized test consists of 100 multiple-choice questions. Each question has five possible answers, only one of which is cor

Nady [450]

Answer:

a) S ~ N ( 0 , 48 )

b) P ( S > 10 ) = 0.0745

Step-by-step explanation:

Given:-

- We have n = 100 MCQs

- 5 options for every MCQs

- probability to guess each MCQ correct is independent from one another.

- Right Answer points= +4

- Wrong answer points= -1

Find:-

a) Find ????(S).

b) Find P(S>10). Write your answer as a math expression, then use the code cell below to find its numerical value and provide it along with your math expression.

Solution:-

- The probability (p) of guessing a correct answer for each question is:

p ( correct answer ) = 1 / 5 = 0.2

- The mean number of correct and incorrect answers can be determined by:

( Mean correct answers) = n*p = 100*0.2 = 20

( Mean incorrect answers) = n*(1-p) = 100*0.8 = 80

- The mean score for correct answers would be:

Sc ( u ) = (Points for right answer)*(Mean correct answers)

Sc ( u ) = ( +4 )*(20)

Sc ( u ) = 80 points

The mean score for incorrect answers would be:

Si ( u ) = (Points for wrong answer)*(Mean incorrect answers)

Si ( u ) = ( -1)*(80)

Si ( u ) = -80 points.

- The mean score attained by a student would be S (u):

S (u) = Sc(u) + Si(u)

S (u) = 80 - 80 = 0

- The variance of the correct and incorrect answers can be determined by:

Var ( correct answers ) = n*p*q = 100*0.2*0.8 = 16

Var ( in-correct answers ) = n*p*q = 100*0.2*0.8 = 16

- The variance of points of correct answers can be:

Sc (Var) = Var ( correct answer ) * (Points for right answer)

Sc (Var) = 16*(+4) = +64 points

- The variance of points of incorrect answers can be:

Si (Var) = Var ( incorrect answer ) * (Points for wrong answer)

Si (Var) = 16*(-1) = -16 points

- Since the probabilities of guessing correct answers are independent. Then as per law of independence:

S ( Var ) = Sc (Var) + Si (Var)

= 64 - 16

= +48 points

- The standard deviation for the distribution (s.d) of points (S) is:

S ( s.d ) = √S (Var) = √48 = 6.9282

- The number of points (S) attained by a student by guessing on the test containing MCQs would have a mean u = 0 points and s.d = + 48 points.

- The random variable (S) can be modeled by normal distribution as follows:

S ~ N ( 0 , 48 )

- To find the required probability P(S>10).

Compute the Z-value of S = 10 points:

Z - value = ( S - u ) / s.d

= ( 10 - 0 ) / 6.9282

= 1.4434

Use the standardized Z-table for normal distribution:

P ( Z > 1.4434 ) = 0.0745

The probability is:

P ( S > 10 ) = P ( Z > 1.4434 ) = 0.0745

5 0

3 years ago

Solve for m. 8m − –6m + –7 = 7

Zigmanuir [339]

Answer:

m=1

Step-by-step explanation:

8m-(-6m)+(-7)=7

8m+6m-7=7

14m=14

m=1

8 0

3 years ago

Read 2 more answers

Please solve, -8-2(7r+1)=-94​

Please solve, -8-2(7r+1)=-94