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.

Related questions
See all questions in Systems Using Substitution
Impact of this question
1812 views around the world
You can reuse this answer
Creative Commons License