Jacob has a total of 70 quarters and dimes that have a combined value of $11.35. How many quarters and dimes are there?

Answer 1

Here's the substitution method:

d + q = 70, so q = 70 - d

10d + 25q = 1135

10d + 25(70 - d) = 1135 Use distributive rule to eliminate parentheses.

10d + 1750 - 25d = 1135 combine like terms, etc.

-15d = -615

d = 41 dimes

q = 70 - 41 = 29 quarters

Answer 2

10d + 25q = 1135

d+q = 70

10d + 10q = 10(70) = 700

25q-10q = 1135-700

15q = 435

q = 435/15 = 29 Quarters

d = 70-29 = 41 Dimes

41(10) +29(25)

= 410 + 725

= 1135

41 Dimes and 29 Quarters