How do solve the following linear system?: x−3y=8,y=8x−3?

1 Answer
EZ as pi · Stefan V.
Apr 28, 2016

x=123 and y=−21523.

Explanation:

One method is to to replace y in the first equation by (8x−3). You can do this because you are told that y has the same value as 8x−3.

This means they are interchangeable. Substituting for y will lead to a linear equation with only one variable, which means you can solve it for x.

x−3(8x−3)=8

x=123

Then use this value for x in the equation y=8x−3 to solve for y. You should get the answers given.

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