At a candy store Erica bought 3 kg of cinnamon red hots and 1 kg of gummy bears for $21 meanwhile Irene bought 3 kg of cinnamon red hots and 3 kg of gummy bears for $39 what is the cost of 1 kg of each type of candy?

You use simultaneous to work this out.

Say c = cinnamon red hots

g = gummbears

3c + 3g = 39

3c + 1g = 21

Since the c's are the same you subtract everything.

So 3c - 3c, 3g-1g, 39-21

2g = 18 (You divide by 2 to get what g is)

g = (So 1kg of gummybears = $9)

To get cinnamon red hots, subsitute the g = 9 into either the first or second equation at the top:

3c + 1g = 21

3c + 9 = 21 (we know that g=9)

3c = 12 (Subtractt 9 from 21)

c = 4 (divide both sides by 3 to get what c is)

So 1kg of cinnamon red hots = $4