Question 1071587
Let {{{ x }}} = her mother's age
{{{ x + 5 }}} = her father's age
{{{ (1/2)*x }}} = the girl's age
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{{{ x + x + 5 + (1/2)*x = 100 }}}
{{{ 2x + (1/2)*x = 100 - 5 }}}
Multiply both sides by {{{ 2 }}}
{{{ 4x + x = 2*95 }}}
{{{ 5x = 190 }}}
{{{ x = 38}}}
and
{{{ (1/2)*x = 19 }}}
and
{{{ x + 5 = 43 }}}
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The girl is 19
Her mother is 38 
Her father is 43