Question 1168527
p pennies
n nickels
d dimes

The 23 coins,  {{{p+n+d=23}}}


The money  $1.51, {{{p+5n+10d=151}}}, accounting to cents.


Other part of description,  {{{2=d/p}}}
or  {{{2p-d=0}}}.


You might want to use the system as  {{{system(p+n+d=23,p+5n+10d=151,2p+0n-d=0)}}} to use but converted to a matrix for your graphing calculator.