Question

pleaseeeeeeee help me.Brady has a collection of dimes and quarters totaling $32.85. she has 171 coins in all. how many of each coin does she have?

Answer 1

d + q = 171 ----> d = 171 - q
.10d + .25q = 32.85
now we will use substitution and plug in 171 - q in for d in the 2nd equation
.10(171 - q) + .25q = 32.85 -- distribute through the parenthesis
17.1 - .10q + .25q = 32.85 --- subtract 17.1 from both sides
-.10q + .25q = 32.85 - 17.1 -- combine terms
0.15q = 15.75 -- divide both sides by 0.15
q = 15.75/0.15
q = 105

d + q = 171
d + 105 = 171
d = 171 - 105
d = 66

check..
.10d + .25q = 32.85
.10(66) + .25(105) = 32.85
6.60 + 26.25 = 32.85
32.85 = 32.85 (correct)

there are 105 quarters (q) and 66 dimes (d)

Answer 2

oh wow thanks I understand it now