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2 years ago

X + 7y = 21 x + 4y = 15 Solve the simultaneous equations

Mathematics

2 answers:

Mariulka [41]2 years ago

8 0

<u>Answer</u>:

x = 7, y = 2

<u>Explanation</u>:

equations given:

x + 7y = 21

x + 4y = 15

make "x" the subject:

x + 7y = 21

x = 21 - 7y .........equation 1

x + 4y = 15

x = 15 - 4y .......equation 2

Solving both the equations simultaneously:

15 - 4y = 21 - 7y

-4y + 7y = 21 - 15

3y = 6

y = 6 ÷ 3

y = 2

If y is 2

Then x = 21 -7y;

x = 21 - 7(2)

x = 21 - 14

x = 7

Yuliya22 [10]2 years ago

6 0

x + 7y= 21

7 goes to RHS = X+ y = 21/7-3

x + 4y = 15

4 goes to RHS= x+y = 15/4 = 3.75

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2 years ago

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3 years ago

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svet-max [94.6K]

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Step-by-step explanation:

According to the question, it is provided that

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Now

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3 years ago

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LUCKY_DIMON [66]

Correct answer: <span>y=1/2x-5
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