Question 688349


{{{2x - y = 4}}}........1
{{{y = 2x - 4}}}..........2
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{{{2x - y = 4}}}......1....solve for {{{y}}}

{{{2x+4 =y}}}.......substitute in 2
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{{{2x+4  = 2x - 4}}}..........2....solve for {{{x}}}

{{{2x-2x= -4 - 4}}}

{{{0= -8}}}............. there are an infinite number of solutions and the 

system is {{{dependent}}}


check it graphically:

{{{2x - y = 4}}}........1
{{{y = 2x - 4}}}..........2
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{{{2x - y = 4}}}........1
{{{-2x+y =-4}}}..........2
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*[invoke solve_by_graphing 2, -1, 4, -2, 1, -4]