Question 575898
{{{ d }}} = number of dimes
{{{ n }}} = number of nickels
given:
{{{ d + n = 30 }}}
{{{ n = 5d }}}
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By substitution:
{{{ d + 5d = 30 }}}
{{{ 6d = 30 }}}
{{{ d = 5 }}}
and, since
{{{ d + n = 30 }}}
{{{ 5 + n = 30 }}}
{{{ n = 25 }}}
He has 25 nickels and 5 dimes
{{{ 25*5 + 5*10 = 175 }}} cents
{{{ 175/100 = 1.75 }}} dollars
He has $1.75