Question 170944
lets call # of dimes and quarters, d and q, respectively
:
d+q=45.........eq 1
.1d+.25q=7.5...eq 2
:
lets rewrite eq 1. to d=45-q.....now take d's value and plug it into eq 2
:
.1(45-q)+.25q=7.5--->distribute
:
4.5-.1q+.25q=7.5---->combine like terms
:
.15q=3
:
{{{highlight(q=20)}}}quarters
{{{highlight(d=45-20=25)}}}dimes