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2 years ago

18. One number is 3 less than a second number. Twice the second number is 12 more than 3 times the first.

Mathematics

1 answer:

bekas [8.4K]2 years ago

4 0

Answer: The numbers are -3 and - 6

Step-by-step explanation:

Let the first number be x and the second number be y , then from the first statement we have

x + 3 = y ............. equation 1

From the second statement

2y = 3x + 12 ............ equation 2

solving the resulting simultaneous equation by substitution method ,we have:

substitute x - 3= y into equation 2 , we have

2( x + 3) = 3x + 12

2x + 6 = 3x + 12

2x - 3x = 6

x = -6

substitute x = - 6 into equation 1 , that is

- 6 + 3 = y

Therefore ,

y = -3

2y = 3y + 3

Check:

x + 3 = y , implies

-6 + 3 = -3 = y

Also 2y = 3x + 12 , implies

2(-3) = -6

3(-6) + 12 = -6

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Solve for x. <br><br> x + 3x + 5 =21

timurjin [86]

Answer:

x=4

Step-by-step explanation:

In order to solve for x, we must isolate x on one side of the equation.

x+3x+5=21

First, combine like terms. x and 3x are both terms with variables, and can be combined.

(x+3x) + 5=21

4x + 5=21

5 is being added to 4x. The inverse of addition is subtraction. Subtract 5 from both sides of the equation.

4x+5-5= 21-5

4x= 16

x is being multiplied by 4. The inverse of multiplication is division. Divide both sides by 4.

4x/4=16/4

x= 16/4

x=4

Let's check our solution. Plug 4 in for x and solve.

x+3x+5=21

4+3(4)+5=21

4+12+5=21

16+5=21

21=21

This solution checks out, so we know our answer is correct.

x is equal to 4, x=4.

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3 years ago

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José was paid an 8 percent commission on the used car that he sold. The used car lot had bought the car from a seller for $8,500

marshall27 [118]

Jose made $816 selling the car.

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2 years ago

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The length of side X is 36.25 cm to the nearest hundredth of a centimeter what is the length of y

goldenfox [79]

Answer:

<h3>The length of y is 62.82 cm.</h3>

Step-by-step explanation:

We are given a right triangle with an angle 30°.

Opposite side of angle 30° is x and adjacent side is y.

Also, given length of side x=36.25 cm.

In order to find the value of y, we need to apply tangent trigonometrical ratio.

We know,

$tan \theta =\frac{Opposite \ Side}{Adjacent \ Side}$

Therefore,

$tan \theta =\frac{x}{y}$

Plugging values of $\theta =30^o$ and x=36.25, we get

$tan 30^o=\frac{36.25}{y}$

Plugging value of $tan 30^o=0.577$ in above equation, we get

$0.577=\frac{36.25}{y}$

On multiplying both sides by y, we get

$0.577\times y=\frac{36.25}{y}\times y$

0.577y=36.25

Dividing both sides by 0.577, we get

$\frac{0.577y}{0.577} =\frac{36.25}{0.577}$

y=62.82

<h3>Therefore, the length of y is 62.82 cm.</h3>

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2 years ago

Suppose the cost of electricity is $0.03 for each kilowatt-hour. Carlos's house runs on 11.14 kilowatt-hours a day. Find the cos

irga5000 [103]

Answer: I think the answer is $33.42

Explanation: If it’s $0.03 for every hour and there is only 11.14 hours used a day just multiply 11.14 by .03 and you get .3342 then you move the decimal over 2 spaces to get 33.42

8 0

2 years ago

Yakvenalex [24]

Answer:

D.648 inches

Step-by-step explanation:

A yard is a unit that mostly used in America and Canadia to measure the length of something field-size, so it's used a lot in sport. One yard equal to three feet, while one foot equals to 12 inches. There is a higher unit than yard called miles which equals to 1760 yards or 1.60934 kilometers.

Since the measurement is 18 yards, the length in feet will be: 18 yards * 3 feet/yard= 54 feet.

The measurement in inch will be: 54 feet * 12 inches/feet = 648 inches.

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2 years ago