Question

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?

Answer 1

Erika $21
3k of cinnamon
1g of gummies

Irene $39
3k of cinnamon
3k of gummies

c= cost of 1 kilogram of cinnamon
g= cost of 1 kilogram of gummies

Erika's Equation
3c + 1g= $21

Irene's Equation
3c + 3g= $39

Solve for one variable in equation one and substitute it in the other equation.

3c + 1g= 21
subtract 3c from both sides
g= 21 - 3c

Substitute g=21 - 3c in equation
3c + 3g= $39
3c + 3 (21 - 3c)= 39
multiply all in parentheses
3c + 63 - 9c= 39
63 - 6c= 39
subtract 63 from both sides
-6c= -24
c= $4

Substitute c=4 in equation to find g
3c + g= 21
3(4) + g= 21
12 + g= 21
subtract 12 from both sides
g= $9

ANSWER: The price of 1 kilogram of cinnamon red hots is $4. The cost of 1 kilogram of gummies is $9.

Hope this helps! :)