SOLUTION: Solve: -12x-3y=-15 4x+y=5

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Question 554865: Solve: -12x-3y=-15
4x+y=5
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!

Start with the given system of equations:
system%28-12x-3y=-15%2C4x%2By=5%29


3%284x%2By%29=3%285%29 Multiply the both sides of the second equation by 3.


12x%2B3y=15 Distribute and multiply.


So we have the new system of equations:
system%28-12x-3y=-15%2C12x%2B3y=15%29


Now add the equations together. You can do this by simply adding the two left sides and the two right sides separately like this:


%28-12x-3y%29%2B%2812x%2B3y%29=%28-15%29%2B%2815%29


%28-12x%2B12x%29%2B%28-3y%2B3y%29=-15%2B15 Group like terms.


0x%2B0y=0 Combine like terms.


0=0Simplify.


Since 0=0 is always true, this means that there are an infinite number of solutions.


So the system is consistent and dependent.


If you need more help, email me at jim_thompson5910@hotmail.com

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Jim