Question 928839
With {{{x}}}= number of dimes, one possible equation is {{{highlight(10x+5(10x)=280)}}} .
So, {{{10x}}}= number of nickels;
{{{10x}}}= value of the {{{x}}} dimes, in cents;
{{{5(10x)}}} number of the {{{10x}}} nickels, in cents,
and {{{10x+5(10x)}}}= total value, in cents, of the dimes and nickels,
which should be {{{280}}} , because that is $2.80, in cents.