At a candy store, erika bought 3 kilograms of cinnamon red hots and 1 kilogram of gummy bears for $21.00. meanwhile, irene bought 3 kilograms of cinnamon red hots and 3 kilograms of gummy bears for $39.00. what is the cost of one kilogram of each type of candy?

If you would like to know the cost of one kilogram of each type of a candy, you can calculate this using the following steps:

1 kilogram of cinnamon red hots ... x = ?
3 kilograms of cinnamon red hots ... 3 * x = ?

1 kilogram of gummy bears ... y = ?
3 kilograms of gummy bears ... 3 * y = ?

Erika: 3 * x + y = $21.00
Irene: 3 * x + 3 * y = $39.00

3 * x + y = 21
3 * x + 3 * y = 39

3 * x + y - (3 * x + 3 * y) = 21 - 39
3 * x + y - 3 * x - 3 * y = - 18
- 2 * y = - 18      /(-2)
y = $9

3 * x + y = $21.00
3 * x = 21 - y
3 * x = 21 - 9
3 * x = 12     /3
x = $4

The correct result would be: 1 kilogram of cinnamon red hots cost $4 and 1 kilogram of gummy bears cost $9.