SOLUTION: y=10x+25 and y=5x+40

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Question 291008: y=10x+25 and y=5x+40
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
y=10x%2B25 Start with the first equation.


5x%2B40=10x%2B25 Plug in y=5x%2B40


5x=10x%2B25-40 Subtract 40 from both sides.


5x-10x=25-40 Subtract 10x from both sides.


-5x=25-40 Combine like terms on the left side.


-5x=-15 Combine like terms on the right side.


x=%28-15%29%2F%28-5%29 Divide both sides by -5 to isolate x.


x=3 Reduce.


y=10x%2B25 Go back to the first equation


y=10%283%29%2B25 Plug in x=3


y=30%2B25 Multiply


y=55 Add.


So the solutions are x=3 and y=55 which form the ordered pair (ie the two graphs intersect at this point).


This means that the system is consistent and independent.