Question 1097683
Not necessarily the neatest way, but...
p pennies
n nickels
d dimes
q quarters


{{{system(1p+5n+10d+25q=191,n-q=1,d/n=2,p-d=8)}}}------four equations in four variables


{{{system(p+5n+10d+25q=191,n-q=1,d=2n,p-d=8)}}}


{{{d=p-8}}}
-
{{{system(p-8=2n,n-q=1,p+5n+10(p-8)+25q=191)}}}


{{{p+5n+10p-80+25q=191}}}
{{{11p+5n+25q=191+80}}}


REVISE in three variables:
{{{system(11p+5n+25q=271,p=2n+8,q=n-1)}}}


Substitute for p and q.
{{{11(2n+8)+5n+25(n-1)=271}}}

{{{22n+88+5n+25n-25=271}}}

{{{52n=271-88+25}}}

{{{52n=208}}}

{{{highlight(n=4)}}} how many nickels-----------you can find the other coins from this.