Question 1033954
(1) {{{ x + y = 1 }}}
(2) {{{ x - 2y = 4 }}}
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Multiply both sides of (1) by {{{ 2 }}}
and add the equations
(1) {{{ 2x + 2y = 2 }}}
(2) {{{ x - 2y = 4 }}}
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{{{ 3x = 6 }}}
{{{ x = 2 }}}
and
(1) {{{ x + y = 1 }}}
(1) {{{ 2 + y = 1 }}}
(1) {{{ y = -1 }}}
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The solution is:
( 2, -1 )
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Here's the plot:
{{{ graph( 400, 400, -6, 6, -6, 6, -x + 1, (1/2)*x - 2 ) }}}