7. alice has a coin purse containing $5.40 in dimes and quarters. there are 24 coins all together. how
many dimes are in the coin purse?

20 quarters 4 dimes

Step-by-step explanation:(Elimination method)

I will replace  0.10,  0.25 and  5.4 by   10  25 and 540 to get rid of the  decimals

D +Q = 24

10D + 25Q = 540

Multiply the first equation by -10

-10D -10Q = -240

10D + 25Q = 540         Subtract the fractions:

0 +     15Q = 300

          Q= 20

    24-20 = 4       4 dimes

4 dimes  =$ 0.40

20 quartes = $5

$5+$0.40=$ 5.40

i think this could be a possible answer (1 / 84) -1

good luck! : d