SOLUTION: need to solve the equation using the substitution method: 3x+4y=6, 2x+8y=9 5x+20y=3, 6x+7y=45

Question 854967: need to solve the equation using the substitution method:
3x+4y=6, 2x+8y=9
5x+20y=3, 6x+7y=45
Answer by KMST(5328) (Show Source): You can put this solution on YOUR website!
Either there are typos, or whoever made up this problem meant to torture students with calculations.

Substitution is not the best method to solve systems like
or .
Substitution works best when one of the coefficients is or .
You look for a coefficient that is "friendly" and solve for that variable.
When none of the coefficients is or substitution makes you work with cumbersome fractions.

For I would solve for ,
--> --> --> ,
and then I would substitute for in the other equation:
--> -->-->-->-->-->-->--> .
Then --> -->-->-->

For I would solve for ,
-->-->--> ,
and then I would substitute for in the other equation:
--> -->-->-->-->-->-->--> .
Then -->-->-->
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