How do you solve the following system?: -3x -2y =5, -4x +7y = -3−3x−2y=5,−4x+7y=−3

1 Answer
Hayden L.
Dec 23, 2015

x=29/13x=2913 and y=-47/13y=−4713

Explanation:

To solve this question there are a number of ways, the most basic being rearrangement and substitution.
To start off you would rearrange the top equation to get y by itself, to do this you would follow these steps
-3x+3x-2y=5+3x−3x+3x−2y=5+3x
Which gives the answer
-2y=5+3x−2y=5+3x
Y isn't by itself yet so you would then:
(-2y)/-2=(5+3x)/-2−2y−2=5+3x−2
Giving the answer
y=-(5+3x)/2y=−5+3x2

Now you must substitute this into the second equation, it would look like this:
-4x+7[(-5+3x)/2]=-3−4x+7[−5+3x2]=−3
You would then simplify to get:
-8x-35+21x=-6−8x−35+21x=−6
Which then simplifies to:
13x=3213x=32
Therefore x=29/13x=2913

Then substitute the value of xx into the equation where y=-(5+3x)/2y=−5+3x2
Which gives the answer:
y=-47/13y=−4713

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