Joe earns $25. He gave Sam $18. His mom gave him $50. He now has $86. What did he begin with?

Question

Joe earns $25. He gave Sam $18. His mom gave him $50. He now has $86. What did he begin with?

Answer 1

Here's what we know:

Joe starts with an unknown amount (J). He gains 25 (+25), loses 18 to Sam (-18), then gains another 50 from his mom (+50). His final total is 86. In mathematical terms, that gives us the following:

J + 25 - 18 + 50 = 86

So from here, we need to remove the known changes until we get to the unknown. Lets start by getting rid of that 50:

J + 25 - 18 + 50 - 50 = 86 - 50

J + 25 - 18 = 36

Now that 25:

J + 25 - 18 - 25 = 36 - 25

J - 18 = 11

And now that -18:

J - 18 + 18 = 11 + 18

J = 11 + 18

Add those numbers together for your final answer.

Answer 2

s represents the starting amount

 

s + 25 - 18 + 50 = 86

 

Can you solve for s and answer?