Solving Systems Equations by Substitution

Chris has $3.85 in dimes and quarters. There are 25 coins in all. How many of each type of coin does he have?

Guest Jul 21, 2020

#1**+1 **

q = # quarters value = 25q

d = #dimes value = 10d

q+ d = 25

25q + 10d = 385 from first equation d = 25-q use this in the second equation

25q + 10(25-q) = 385 now you can solve for q then d = 25-q

25q+250-10q = 385

15q= 135

q = 9 quarters d = 25 - q = .......

ElectricPavlov Jul 21, 2020