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4 years ago

X+y=3 3x-y=-7 elimination method

Mathematics

1 answer:

Alina [70]4 years ago

3 0

x + y = 3

+ x - y = -7

-------------------

2x = -4

x = -2

-2 + y = 3

y = 5

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Find the 1st , 2nd (median) and 3rd quartile of the set of numbers 6,8,2,6,7,9 ?

zubka84 [21]

Answer:

at first we put the numbers in order from least to greatest

2 , 6 , 6 , 7 , 8 , 9

1st quartile = 6

median = (6+7)/2 = 6.5

3rd quartile = 8

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3 years ago

Which expression simplifies to 41? Choose all that apply!

Arada [10]

Answer:

None of the expressions is simplified to 41.

Step-by-step explanation:

You have to follow the P.E.M.D.A.S., this is:

P:Parentheses first.

E:Exponent next.

M:Multiplication.

D:Division.

(Multiplication and Division is whichever come first, from left to right)

A: Addition.

S: Subtraction.

(Addition and Subtraction is whichever come first, from left to right).

<u><em>We are going to analyze every option:</em></u>

1. 10+ 2.4 - 1

First we have to solve the multiplication:

$10+ 2.4 - 1=10+8-1$

Now we have to solve the addition and subtraction from left to right:

$10+8-1=18-1=17\neq 41$

This is not a correct answer.

2. 10+2.(4-1)

We have to solve the parentheses first:

$10+2.(4-1)=10+2.(3)$

Now the multiplication and then the addition.

$10+2.(3)=10+6=16\neq 41$

This is not a correct answer.

3. (10+23).4-1

We have to solve the parentheses first:

$(10+23).4-1=(33).4-1$

Now the multiplication and then the subtraction:

$(33).4-1=132-1=131\neq 41$

This is not a correct option.

4. $10+(2^2.4)-1$

We have to solve the parentheses first, in the parenthesis first we have to solve: $2^2$ and then do the multiplication.

$10+(2^2.4)-1=10+(4.4)-1=10+16-1$

Now we have to solve the addition and subtraction from left to right:

$10+16-1=26-1=25\neq 41$

This expression is not a correct option.

Then none of the expressions is simplified to 41.

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3 years ago

If you take half my age and add 7, you get my age 13 years ago. How old am I?

mestny [16]

Answer:

You are currently 40 years old

Step-by-step explanation:

Let's say the current age is represented by the variable x.

x = current age

The question says that "if you take half my age and add 7, you get my age 13 years ago"

This can be represented like this:

1/2(x) + 7 = x - 13

Now we solve for x using basic algebra:

1/2(x) = x - 20

-1/2(x) = -20

x = 40

To check if this is correct, plug it back into the equation and see if both sides equal each other:

1/2(40) + 7 = (40) - 13

20 + 7 = 27

27 = 27

Hope this helps (●'◡'●)

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Maybe A
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3 years ago

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Area is equals length times (*) breath
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3 years ago