Math magic!

Here’s a magic trick I’m doing with my students….
1. Pick any number.
2. Multiply that number by -3
3. Add 2
4. Multiply by 5
5. Add 15 times your original number.
Abracadabra…. you’re left with the number 10!    (and if you’re not, double-check your math!)

Curious?? How about another one…
1. Pick a number
2. Multiply that number by -4
3. Add 10
4. Multiply by 2
5. Add 8 times your original number
Alacazam…. you’re left with the number 20!  (or double-check your math!!)

I guess this is the closest I’ll ever get to Hogwarts!!
Anyone have an idea how it works!??!

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