Mathword problem

Question

a jar contains 47 quarters and pennies. the total value of the coins is $4.55. which system of equations can be used to find p, the number of pennies, and q, the number of quarters

Answer 1

q+p =47

25q + p =455

17 quarters and 30 pennies = $4.55

q<19 if q=19, 25x19 = 475>455

q=18, 25x18 = 450 and p=5, but 18+5 =23, not 47

q=17, 25x17 = 425 with p =30, 17+30 = 47

q + p =47, multiply by 25 to get

25q +25p=1175

subtract 25q+p = 455 to eliminate one variable

24p =720

p=720/24 = 30 pennies

q = 47-30 = 17 quarters