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lisabon 2012 [21]
3 years ago
7

Please help me solve 3x + 4y =15 and 3x - y = 30 it is for Algebra I

Mathematics
2 answers:
Makovka662 [10]3 years ago
7 0

Answer:

Step-by-step explanation:

Given the simultaneous equation

3x+4y=15. Equation 1

3x-y=30. Equation 2

Using elimination method

Sutract equation 2 from 1

Then, will have

3x-3x+4y--y=15-50. -×-=+

4y+y=-15

5y=-15

Divide Both sides by 5

y=-15/5

y=-3

From equation 2

3x-y=30

3x--3=30

3x+3=30

3x=30-3

3x=27

Divide both side by 3

x=27/3

x=9

Then, x=9 and y=-3

Colt1911 [192]3 years ago
7 0

Answer:

x=7 y=-9

Step-by-step explanation:

Use a system of equations to solve.

3x-y=30 changes to y=-30+3x

This can then be substituted into the other equation.

3x+4(-30+3x)=15

solve for x

X=7

Now use 7 in the other equation.

y=-30+x(7)

y=-9

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 Clearing r we have:
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3 years ago
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Ebony’s bank balance is $400 was Day 8 and this can be explained below.

<h3>How to explain the information?</h3>

Jade cannot be true because for every transaction made during withdraws, a little amount of money is collected and as such the amount will never remain $400.

Note that the scenario for the above to occur is:

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