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astra-53 [7]
2 years ago
8

19. The present age of brother and sister are in the ration 4:5 Before three years the ration of their age was 3:4. find their p

resent age-​
Mathematics
1 answer:
Lyrx [107]2 years ago
5 0

Answer:

Sister = 15 years old

Brother = 12 years old

Step-by-step explanation:

Right now, if the brother is B years old and the sister is S years old, B = (4/5)S because the ratio from brother to sister is 4:5, so if one unit is X, B = 4X and S = 5X

Three years ago, the brother was B-3 years old and the sister was S-3 years old. Keeping one unit as X, we have

B = 3X

S = 4X

B-3 = (3/4)(S-3)

Therefore, we have a system of equations

B = (4/5)S

B-3 = (3/4)(S-3)

Substitute (4/5)S for B into the second equation to only have one variable

(4/5)S - 3 = (3/4)(S-3)

(4/5)S - 3 = (3/4)S - 9/4

add 3 to both sides and subtract (3/4)S from both sides to isolate the variable and its coefficient

(1/20)S = 3/4

multiply both sides by 20 to isolate the S

S = 15

B = (4/5)S = 12

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Step-by-step explanation:

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Weapon of math destruction trig. day 1
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The questions are illustrations of trigonometry ratios and right triangles

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Trigonometry ratio

Trigonometry ratios are very useful in determining the measure of angles, and the side lengths of a right triangle.

<h3>Question 1</h3>

The value of x is calculated using the following sine trigonometry ratio

\sin(25) =\frac{5}{x}

Make x the subject

x =\frac{5}{\sin(25)}

This gives

x =11.8310

Hence, the value of x is 11.8310

<h3>Question 2</h3>

This question is illustrated by the first diagram in the attached figure

The height (h) of the tree is calculated using the following tangent trigonometry ratio

\tan(25) =\frac{h}{50}

Make h the subject

h = 50 \times \tan(25)

This gives

h = 23.3154

Hence, the tree is 23.3154 feet tall

<h3>Question 3</h3>

This question is illustrated by the second diagram in the attached figure

The depth (h) of the sub is calculated using the following tangent trigonometry ratio

\tan(37) =\frac{h}{500}

Make h the subject

h = 500 \times \tan(37)

This gives

h = 376.7770

Hence, the depth of the sub is 376.7770 meters

Read more about trigonometry ratios at:

brainly.com/question/6241673

8 0
3 years ago
julio distributed a survey to his fellow students asking them how many hours they spent playing sports in the past day. He also
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Answer:

The least mood value.

Step-by-step explanation:

If Julio has rated their mood on a scale from 0 to 10, with 10 being the happiest. The least value is 5.

If the fitted line has a y-intercept of 5, the best interpretation of this y-intercept is that the least mood value among the his fellow students is 5.

Intercept actually means beginning, starting point, flat rate e.t.c

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A letter/symbol that takes place of an unknown number?
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Step-by-step explanation:

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The perimeter of a rectangle is 22 inches. Find the dimensions if its length is 3 inches greater than its width.
MaRussiya [10]

Answer:

Length: 7

Width: 4

Step-by-step explanation:

We can create a system of equations for this problem, where w is the width and l is the length.

The perimeter of a rectangle is twice its length added to twice its width.

2l+2w=22

The length is 3 more than the width:

l = w+3

We can now substitute in w+3 as l in the equation 2l+2w=22.

2(w+3) + 2w = 22

Distribute the first terms:

2w+6+2w=22

Combine like terms:

4w+6=22

Subtract 6 from both sides:

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Divide both sides by 4:

w = 4

Now we know that w = 4. We can now substitute this inside an equation to find l.

l = w+3\\\\l = 4+3\\\\l=7

Hope this helped!

7 0
3 years ago
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