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

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

# x=1/23# and #y = -2 15/23#.

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 = 1/23#

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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