Question 316821
1.{{{N=Q+7}}}
2.{{{5N+25Q=275}}}
Substitute eq. 1 into eq. 2,
{{{5(Q+7)+25Q=275}}}
{{{5Q+35+25Q=275}}}
{{{30Q+35=275}}}
{{{30Q=240}}}
{{{highlight( Q=8)}}}
Then from eq. 1,
{{{N=8+7}}}
{{{highlight(N=15)}}}
There are 15 nickels.