Question 410760
{{{d}}} = number of dimes
{{{q}}} = number of quarters
(1) {{{d + q = 250}}}
(2) {{{10d + 25q = 3925}}} (in cents)
Multiply both sides of (1) by {{{10}}}
and subtract (1) from (2)
(2) {{{10d + 25q = 3925}}}
(1) {{{-10d - 10q = -2500}}}
{{{15q = 1425}}}
{{{q = 95}}}
{{{d = 250 - 95}}}
{{{d = 155}}}
There are 155 dimes and 95 quarters
check answer:
(2) {{{10d + 25q = 3925}}}
(2) {{{10*155 + 25*95 = 3925}}}
{{{1550 + 2375 = 3925}}}
{{{3925 = 3925}}}
OK