Question

Clara has 8 coins worth 17¢. if the coins are all dimes and pennies, how many dimes and pennies does she have?

Answer 1

Let x = the number of dimes
Let y =  the number of pennies.

There are 8 coins, therefore
x + y = 8        (1)

The coins are worth 17 cents, therefore
10x + y = 17     (2)

Subtract equation (1) from equation (2).
10x + y - (x + y) = 17 - 8
9x = 9
x = 1

From (1), obtain
y = 8 -x = 8 - 1 = 7

Answer: 1 dime, 7 pennies.

Answer 2

One dime, seven pennies