SOLUTION: It's been a long time since I've done algebra....I'm a 43 yr old Dad...trying to help my 15 yr old daughter with homework (she's gone right now) explain to me if you please how to

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Question 54202: It's been a long time since I've done algebra....I'm a 43 yr old Dad...trying to help my 15 yr old daughter with homework (she's gone right now) explain to me if you please how to solve this equation:
2x - 5y =9
y = 3X - 7
Thanks for your help in advance.....Don Gillis
Answer by Nate(3500) About Me  (Show Source):
You can put this solution on YOUR website!
There are two main ways of easily solving these, but you would simply use substitution.
Remember, the y value is equal to 3x+-+7. You would just put that value in for the second equation.
2x - 5y = 9
2x - 5(3x - 7) = 9
2x - 15x + 35 = 9
-13x = -26
x = 2
Remember: y+=+3x+-+7
y+=+3%282%29+-+7+=+6+-+7+=+-1
Answer: x = 2 and y = -1
You can also solve this by graphing each line:
graph%28300%2C300%2C-5%2C5%2C-5%2C5%2C3x+-+7%2C%282x-9%29%2F5%29