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3 years ago

4x - 2y = -20 7x + 2y = -2

Mathematics

1 answer:

Brut [27]3 years ago

8 0

Answer:

(-2, 6)

General Formulas and Concepts:

Pre-Algebra

Order of Operations: BPEMDAS
Equality Properties

Algebra I

Solving systems of equations using substitution/elimination
Solving systems of equations by graphing

Step-by-step explanation:

Step 1: Define systems

4x - 2y = -20

7x + 2y = -2

Step 2: Rewrite systems

4x - 2y = -20

Add 2y to both sides: 4x = 2y - 20
Divide 4 on both sides: x = 1/2y - 5

Step 3: Redefine systems

x = 1/2y - 5

7x + 2y = -2

Step 4: Solve for y

Substitution

Substitute in x: 7(1/2y - 5) + 2y = =-2
Distribute 7: 7/2y - 35 + 2y = -2
Combine like terms: 11/2y - 35 = -2
Add 35 to both sides: 11/2y = 33
Isolate y: y = 6

Step 5: Solve for x

Define original equation: 7x + 2y = -2
Substitute in y: 7x + 2(6) = -2
Multiply: 7x + 12 = -2
Subtract 12 on both sides: 7x = -14
Divide 7 on both sides: x = -2

Step 6: Graph systems

Check the system.

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3 years ago

How many 1/8 teaspoons are equal to 4 3/4 teaspoons?

Vinvika [58]

1. Convert fraction into same decimal.

To find this answer, we want to first convert the fraction so that the denominators are the same:

3/4 = ?/8

Divide the original denominator by the needed-to-be denominator.

8 / 4 = 2

Do reversal calculations

4 x 2 = 8

So, now that we know to multiply the original denominator by 2 to get the new denominator, multiple the numeriator by the same.

3 6

_ x 2 = _

4 8

So now, the new equation is:

How many 1/8 teaspoons are equal to 4 6/8 teaspoons.

(The reason why you must convert is because then you can simply say that the fraction is 6 1/8's, which means you just have to worry about the whole numbers.

2. Convert the whole numbers into a fraction to make it easier.

In order to convert whole numbers into fractions, first find the denominator your using. Which in this case, it is 8.

?/8

Now remember, for it to be a whole number, the numeriator and denominator MUST be the same.

8/8 = 1

Now remember, there are four 1's. Multiply the numeriator by 4, but keep the denominator the same or else the equation is ruined.

32/8 = 4

3. Add all your information together.

DO NOT forget to add the information you collected during the equation, or else you will get a wrong answer. Add the equation's final answer to the whole numbers final answer.

32 / 8 + 6 / 8 = ?

32 / 8 + 6 / 8 = 38 / 8

Well now, remember something. It is asking us, how many 1/8's were in the equation 4 3/4. We have transformed 4 3/4 into a whole equation, 38/8.

Now, all you need to do is look at the numeriator.

What number do you see?

You see 38.

The denominator is the correct denominator that you need. So, the number of the numeriator is the answer to the equation.

So, how many 1/8 are in 38/8?

38!

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4 years ago

A company collected $7,800 by selling shoes. The company had $6,084 left after paying the tax. What was the percentage of tax?

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Answer:

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The percentage of tax can be found by calculating the percent change.

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3 years ago