SOLUTION: using the substituion method 9x+7y=9 and x=57-7y

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Question 279811: using the substituion method 9x+7y=9 and x=57-7y
Answer by JenniferTutors(83) About Me  (Show Source):
You can put this solution on YOUR website!
To solve this equation with substitution method:
9x%2B7y=9and x=57-7y
First, looking at the two equations, you notice that the second one is already in the form of "x equals." You can take this and place into the other equation in place of the variable x, shown below:
9%2857-7y%29%2B7y=+9
Next, you multiply 9 by the terms in the parenthesis:
9 x 57 = 513
9 x -7y = -63y
513-63y%2B7y=+9
Combine like terms, the y's in this equation:
513-56y=+9
Now get y by itself by subtracting 513 to the other side of the equation:
-56y=+9-513
-56y=+-504
Next, divide -56 to both sides of the equal sign:
-56y%2F-56+=+-504%2F-56
remember: negative divided by a negative equals a positive
y=+9
Now place the value of y into the second equation from the beginning:
x=57-7%289%29
x=57-63
x=-6
You can check your answers, place the x=-6 and y=9 into the original equations and they are correct.