SOLUTION: y=x+5 and -3x+3y=15

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Question 132477This question is from textbook Algebra 1
: y=x+5 and -3x+3y=15This question is from textbook Algebra 1

Answer by jim_thompson5910(21685) About Me  (Show Source):
You can put this solution on YOUR website!
Start with the given system
-3x%2B3y=15
y=x%2B5



-3x%2B3%28x%2B5%29=15 Plug in y=x%2B5 into the first equation. In other words, replace each y with x%2B5. Notice we've eliminated the y variables. So we now have a simple equation with one unknown.


-3x%2B3x%2B15=15 Distribute


15=15 Combine like terms on the left side


0=15-15Subtract 15 from both sides


0=0 Combine like terms on the right side



Since this equation is always true for any x value, this means x can equal any number. So there are an infinite number of solutions.