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3 years ago

2x + y = 3 x - 2y = -1 If equation two is multiplied by -2 and then the equations are added, the result is what?

Mathematics

1 answer:

photoshop1234 [79]3 years ago

5 0

Answer:

2x + y
3 x - 2y
-1

2(3 x - 2y) = -6x + 4y

2x + y + -6x + 4y + -1 = -4x + 5y -1

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Divide 250 in the ratio of 1 : 4

Aleksandr [31]

1 + 4 = 5 (5 parts)
£250/5 = 50 
1 x £50 = 50 
4 x £50 = 200 
so the answer is 50:200

6 0

3 years ago

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A triangle has base 15ft and area 60ft2. What is the height?j

hoa [83]

The height is 4 feet. You calculate the area by length times height. So what multiplied by 15 is 60? Well, 15ft x 4ft = 60ft^2

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3 years ago

How is the series 5+11+17…+251 represented in summation notation?

NISA [10]

Answer:

$\displaystyle \large{\sum_{n=1}^{42}(6n-1)$

Step-by-step explanation:

Given:

Series 5+11+17+...+251

To find:

Summation notation of the given series

Summation Notation:

$\displaystyle \large{\sum_{k=1}^n a_k}$

Where n is the number of terms and $\displaystyle \large{a_k}$ is general term.

First, determine what kind of series it is, there are two main series that everyone should know:

Arithmetic Series

A series that has common difference.

Geometric Series

A series that has common ratio.

If you notice and keep subtracting the next term with previous term:

11-5 = 6
17-11 = 6

Two common difference, we can in fact say that the series is arithmetic one. Since we know the type of series, we have to find the number of terms.

Now that brings us to arithmetic sequence, we know that first term is 5 and last term is 251, we’ll be finding both general term and number of term using arithmetic sequence:

Arithmetic Sequence

$\displaystyle \large{a_n=a_1+(n-1)d}$

Where $\displaystyle \large{a_n}$ is the nth term, $\displaystyle \large{a_1}$ is the first term and $\displaystyle \large{d}$ is the common difference:

So for our general term:

$\displaystyle \large{a_n=5+(n-1)6}\\\displaystyle \large{a_n=5+6n-6}\\\displaystyle \large{a_n=6n-1}$

And for number of terms, substitute $\displaystyle \large{a_n}$ = 251 and solve for n:

$\displaystyle \large{251=6n-1}\\\displaystyle \large{252=6n}\\\displaystyle \large{n=42}$

Now we can convert the series to summation notation as given the formula above, substitute as we get:

$\displaystyle \large{\sum_{n=1}^{42}(6n-1)$

5 0

2 years ago

Please help!!!

Likurg_2 [28]

Answer: Hello! I believe your answer would be 162.

Step-by-step explanation: So the formula for Area on a rectangle is WxL. So length will be 9. But if you notice on the scale rectangle the width is the length times two. So the length on the real garden is 18.

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3 years ago

It costs Mrs. Smith $4.00 to make a pie. She sells them for $12 each. What is the Markup rate (percent)?

nignag [31]

70% I think beacuse she is making more profit about 70% then she bought it for

4 0

2 years ago

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