SOLUTION: I am stuck on elimination by substitution. The variable has to be "naked" or alone, but both x and y have numbers before the variables.

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Question 751292: I am stuck on elimination by substitution. The variable has to be "naked" or alone, but both x and y have numbers before the variables.
Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
Ax%2BBy=C+
Dx%2BCy=E

A process to eliminate terms of y.
E%28Ax%2BBy=C%29
B%28Dx%2BEy=F%29
Note each entire equation is being multiplied.
AEx%2BBEy=E%2AC
BDx%2BEBy=B%2AF
We may sometimes apply commutative property of multiplication,
AEx%2BBEy=CE
BDx%2BBEy=BF

Subtract one equation from the other equation:
AEx%2BBEy-BDx-BEy=CE-BF
And this is how we have the term, "elimination method".

In this general case, symbolically giving
AEx-BDx=CE-BF, or %28AE-BD%29x=CE-BF, and then division by the coefficient expression on x,
highlight%28x=%28CE-BF%29%2F%28AE-BD%29%29