Question 1131461
{{{ 2x - y = 3 }}}
{{{ x + y = 12 }}}
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Add the equations
{{{ 3x = 15 }}}
{{{ x = 5 }}}
Put this result back into either of the equations
{{{ x + y = 12 }}}
{{{ 5 + y = 12 }}}
Subtract {{{ 5 }}} from both sides
{{{ y = 12 - 5 }}}
{{{ y = 7 }}}
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The solution is ( 5, 7 )
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check:
{{{ 2x - y = 3 }}}
{{{ 2*5 - 7 = 3 }}}
{{{ 10 - 7 = 3 }}}
{{{ 3 = 3 }}}
OK