Question 922374

{{{x + y = 2}}}.....eq.1

{{{x - y = 4}}}.........eq.2
_________________________________add both

{{{x + y +(x - y)= 2+4}}}

{{{x +cross (y) +x - cross(y)= 6}}}

{{{x  +x = 6}}}

{{{2x= 6}}}

{{{x= 6/2}}}

{{{highlight(x= 3)}}}

go back to eq.1 or eq.2, plug in {{{3}}} for {{{x}}} and find {{{y}}} 

{{{3 - y = 4}}}.........eq.2

{{{3 - y+y = 4+y}}}

{{{3= 4+y}}}

{{{3-4= 4-4+y}}}

{{{-1=y}}}

{{{highlight(y=-1)}}}

see it on a graph:

{{{drawing( 600, 600, -10, 10, -10, 10,circle(3,-1,.15),locate(3,-1,p(3,-1)), graph( 600, 600, -10, 10, -10, 10, -x+2, x-4)) }}}