SOLUTION: srry lost my other account password the ones next to each other are all one problem x=y+1 x+2y=7 3x-y=2 y=2x-9

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Question 130247: srry lost my other account password the ones next to each other are all one problem

x=y+1 x+2y=7

3x-y=2 y=2x-9





Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
# 1

Start with the given system
x%2B2y=7
x=y%2B1



y%2B1%2B2y=7 Plug in x=y%2B1 into the first equation. In other words, replace each x with y%2B1. Notice we've eliminated the x variables. So we now have a simple equation with one unknown.




3y%2B1=7 Combine like terms on the left side


3y=7-1Subtract 1 from both sides


3y=6 Combine like terms on the right side


y=%286%29%2F%283%29 Divide both sides by 3 to isolate y



y=2 Divide




Now that we know that y=2, we can plug this into x=y%2B1 to find x



x=%282%29%2B1 Substitute 2 for each y


x=3 Simplify


So our answer is x=3 and y=2 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+5%2C+%287-x%29%2F%282%29%2C+x-1%29+ Graph of x%2B2y=7 (red) and x=y%2B1 (green)







# 2


Start with the given system
3x-y=2
y=2x-9



3x-%282x-9%29=2 Plug in y=2x-9 into the first equation. In other words, replace each y with 2x-9. Notice we've eliminated the y variables. So we now have a simple equation with one unknown.


3x-2x%2B9=2 Distribute the negative


x%2B9=2 Combine like terms on the left side


x=2-9Subtract 9 from both sides


x=-7 Combine like terms on the right side




Now that we know that x=-7, we can plug this into y=2x-9 to find y



y=2%28-7%29-9 Substitute -7 for each x


y=-23 Simplify


So our answer is x=-7 and y=-23 which also looks like