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What is the solution to the system of equations? (7, 9) (9, 7) (–5, 11) (11, –5)

What is the solution to the system of equations? (7, 9) (9, 7) (–5, 11) (11, –5)-example-1
User Burning
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2 Answers

5 votes

Answer: (7,9)

Explanation:

Took the test :)

User Ionut Bajescu
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2 votes

Answer: (7, 9)

Step-by-step explanation: To solve this system, I would use addition.

To solve a system of equations by addition,

we need one of our variables to cancel out.

Notice that we have a 4x in our first equation.

If we had a -4x in our second equation, the x's would cancel.

To create a -4x in the second equation,

we must multiply the entire equation by -4.

So we have (-4)(x + 6y) = (61)(-4).

Rewriting this equation, we have -4x - 24y = -244.

Now let's rewrite both equations.

4x - 5y = -17

-4x - 24y = -244

_____________

Now when we add the equations together, the x's cancel.

So we're left with -29y = -261.

Now divide both sides by -29 and we have y = 9.

To find x, we plug a y back in for x in either equation.

So let's go with our second equation, x + 6y = 61.

Plugging a 9 in for y, we have x + 6(9) = 61 or x + 54 = 61.

Subtracting 54 from both sides, we have x = 7.

So x = 7 and y = 9 which we can write as the ordered pair (7, 9).

User Saurav Srivastava
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