beverly has quarters and dimes, she has 21 coins with a total value of $3.00 how many quarters and dimes does she have?

Question

secretx_x · Answer

Well, 10 dimes equals one dollar.. 
4 quarters equals one dollar.. 
What do you think?

quickstudent · Answer

I would say there are 6 quarters and 5 dimes.

secretx_x · Answer

You need to have an equivalent to 21 coins @quickstudent

quickstudent · Answer

Oh, ya! sorry that was a mistake.

secretx_x · Answer

It's okay, I think you're on the right track to helping the user. Keep going!

jdoe0001 · Answer

q = quarters amount
d = dimes amount

she has 21 of those
so
$\bf \large q + d = 21$

1q = 25c
1d = 10c

total value is $3.00, or 300c

thus we could say that

25q   is however amount of cents in the quarters there are
10d  is however amount of cents in the dimes there are

thus

$\large \bf 25q + 10d = 300  $

jdoe0001 · Answer

solve by substitution

quickstudent · Answer

@secretx_x , I busy now, can you continue?