How do you solve the system by substitution #x + y = 12# and #y = 2x#?

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Answer 1 · 2016-10-01T14:20:41

Solution is #x=4# and #y=8#

We have two equations #x+y=12# and #y=2x#

Let us substitute value of #y# from second equation in the first equation.

As #y=2x#, substituting this in first we get

#x+2x=12#

or #3x=12#

or #x=12/3=4#

and hence #y=2x=2xx4=8#, therefore

Solution is #x=4# and #y=8#