Math help! please explain this to me?

Question

how would i set up an equation for this.

A parking meter takes only dimes and quarters. At the end of the day, the number of dimes int eh meter is eight more than twenty times the number of quarters. the value of the coins in the meter is $7.55. Find the number of quarters and dimes in the meter.

im in 9th grade, algebra.

please help, or give me a webiste that would help me out

Answer 1

ok... so you have 2 equations

d(# of dimes)=20q(#of quarters)+8

.10d+.25q=7.55

you can guess and check, just plug in the number of quarters in q and the number of dimes in d in the second equation

1 quarter and 28 dimes= 3.05

2 quarters and 48 dimes= 5.30

3 quarters and 68 dimes= 7.55

Answer 2

20q + 8 = d

.10d + .25q = 7.55

q = number of quarters, d = number of dimes

Solve any way you like!

Answer 3

20q +8 = d

10d +25q = 755

10(20q +8 ) +25q = 755

200q +80 +25q = 755

225q + 80 = 755

225q = 755-80

225q = 675

q = 675/225=3

so knowign no of quarters =3

20*3 +8 = d = 68