SOLUTION: Y=5X+5 Y=15X-1

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Question 132471: Y=5X+5
Y=15X-1
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
Start with the given system
y=5x%2B5
y=15x-1



15x-1=5x%2B5 Plug in y=15x-1 into the first equation. In other words, replace each y with 15x-1. Notice we've eliminated the y variables. So we now have a simple equation with one unknown.



15x=5x%2B5%2B1Add 1 to both sides


15x-5x=5%2B1 Subtract 5x from both sides


10x=5%2B1 Combine like terms on the left side


10x=6 Combine like terms on the right side


x=%286%29%2F%2810%29 Divide both sides by 10 to isolate x



x=3%2F5 Reduce




Now that we know that x=3%2F5, we can plug this into y=15x-1 to find y



y=15%283%2F5%29-1 Substitute 3%2F5 for each x


y=8 Simplify


So our answer is x=3%2F5 and y=8 which also looks like



Notice if we graph the two equations, we can see that their intersection is at . So this verifies our answer.


+graph%28+500%2C+500%2C+-5%2C+5%2C+-5%2C+10%2C+5x%2B5%2C+15x-1%29+ Graph of y=5x%2B5 (red) and y=15x-1 (green)