Question 1199658
$1.25 in nickels and dimes, 18 coins


d dimes
18-d nickels
{{{10d+5(18-d)=125}}}


{{{10d+5*18-5d=125}}}

{{{(10-5)d=125-5*18}}}

{{{d=(125-5*18)/(10-5)}}}------simplify and compute.

{{{d=(5*5*5-5*18)/5}}}

{{{d=25-18}}}

{{{highlight(d=7)}}}---------{{{nickels=11}}}