1. Solve: Eight coins (dimes and quarters) are worth 170 cents. How many
dimes are there? 2. Solve: Eleven coins (dimes and nickels) are worth 60 cents. How many
dimes are there? 3. Eleven coins (dimes and quarters) are worth 170 cents. How many
dimes are there?
#1. add up the value of the coins. Note that if there are d dimes, then the rest (8-d) are quarters. That means that the value of the coins is
10d + 25(8-d) = 170
Now just solve for d.
Now do the others in like wise.