SOLUTION: solve the system of equations: verify the solution by replacing the values in the original equations; y= 3x-7 y= -x+9 I am just not understanding what they want done.

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Question 1106664: solve the system of equations:
verify the solution by replacing the values in the original equations;
y= 3x-7
y= -x+9
I am just not understanding what they want done.
Answer by ikleyn(52787) About Me  (Show Source):
You can put this solution on YOUR website!
.
1. The solution 

Look into the two equations. Their left sides are IDENTICAL, right ?


Hence, their right sides are equal:

3x - 7 = -x + 9

3x + x = 9 + 7

4x = 16  ====>  x = 16%2F4 = 4.


Then from the first equation y = 3x-7 = 3*4 - 7 = 12-7 = 5.


Answer.  x= 4,  y= 5.


2. Checking / (verifying) 

Substitute the obtained values x= 5, y= 5 into the original equations.


a)  First equation becomes  5 = 3*4 - 7.   Is is true ?   - YES, it is.  Thus first equation is just checked.


b)  Second equation becomes  5 = -4 + 9.   Is it TRUE ?  -  YES, it is.  Thus second equation is just checked, too.

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The check is completed.

The solution is completed.

You are done.