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Aleks04 [339]
2 years ago
7

HELP PLS ITS URGENT

Mathematics
1 answer:
marysya [2.9K]2 years ago
3 0

Melanie: 15 years old

Kevin: 5 years old

Assume Kevin's present age is x.

That means that 3 years ago, his age would be x - 3.

Melanie's age would be 6(x - 3).

Same thing for 5 years into the future:

Kevin's age would be x + 5.

Melanie's age would be 2(x + 5).

The two equations we have here are:

\left \{ {{x + 5 = 2(x + 5)} \atop {x - 3 = 6(x - 3)}} \right.

By subtracting both equations, we are simplified to:

8 = -4x + 28

By solving the equation, we get x = 5.

That means that Kevin's current age is 5 years old.

Melanie's age could be calculated by substituting Kevins'.

6(x - 3) --> 6(5 - 3) --> 12

Since that was 3 years ago, you need to add 3 to 12 to get her current age.

12 + 3 = 15

Melanie's current age is 15 years old.

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3 years ago
If you know the 7x8=56 how can you use the Commutative Property of Multiplication to find the product of 8x7?
boyakko [2]

Answer:

The communicative property for multiplication states that the order of the multiplicands and can be swapped and the resulting product stays the same.

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So if

7*8=56

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8*7=56 as well since you can swap the order of the terms on the left and not change the result.

This property is true for addition and multiplication. It does not hold for subtraction or division.

Hope that makes sense and helps. (:

5 0
3 years ago
The cost of a stove to a store owner was $500, and she sold the stove for $1080. What was her percent of profit based on cost?
Juliette [100K]

Answer:

116%

Step-by-step explanation:

Cost Price (C. P.) = $500

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Profit = SP - CP = $1080 - $500 = $580

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2 years ago
Write two expressions to show w increased by 4. Then, draw models to prove that both expressions represent the same thing.
Vinil7 [7]

Answer:Answer:

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Step-by-step explanation:

Given phrase,

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By the commutative property of addition,

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For drawing a model that shows w + 4

Take two boxes in which first shows w and second shows 4 and add them,

Similarly, for showing 4 + w, take first box that shows 4 and second box that shows w then add them.

Step-by-step explanation:

7 0
3 years ago
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Which expression is equivalent to (4^−3)^−6?
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Answer

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i hope this is what your looking for

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