You can
put this solution on YOUR website!she has 3 more nickles than quarters=x+3
quarters=x
she has two times as many dimes as quarters=2x
nickles: multiply (x+3)by (.05)
quarters: multiply (x) by (.25)
dimes: multiply 2x by .10
(x+3)(.05)+(x)(.25)+(2x)(.10)=3.15
0.05x+0.15 +0.25x+0.20x=3.15
0.50x+0.15=3.15 <--subtract both sides by .15
(0.50x+0.15)-0.15=(3.15)-0.15
0.50x=3 <--divide both sides by .5

=

x=6
since quarters=x, and x=6 she has 6 quarters
nickles=x+3=6+3=9 nickles
dimes=2x=2(6)=12 dimes
check: 6($0.25)+9($0.05)+12($0.10)
$1.50+$0.45+$1.20=$3.15