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Solve the system by using a table.
{3y = 4x + 7
{-4x - 4y = 28

1 Answer

3 votes

Answer:

The two equations given in the question are:

3y = 4x + 7

- 4x - 4y = 28

Now, let us subtract 3y and 7 from both sides of the first equation

3y - 3y - 7 = 4x + 7 - 3y - 7

- 7 = 4x - 3y

This can be written as

4x - 3y = - 7

Now let us set the two equations in table form

4x - 3y = - 7

- 4x - 4y = 28

We get from the above deduction,

- 7y = 21

y = - 21/7

y = - 3

Now let us put the value of y in the first equation, we get

3y = 4x + 7

3 (- 3) = 4x + 7

- 9 = 4x + 7

4x = - 9 - 7

4x = - 16

x - - 4

So (x,y) comes out to be (-4, -3). The correct option among all the options given in the question is the first option or option "A".

please add options

User Astasiak
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