Why is 3^20 + 3^20 + 3^20 == 3^21 ??!? I'm so confused

Question

turingtest · Answer

3^20+3^20+3^20
combine like terms...
=3(3^20)=3^(20+1)=3^21

anonymous · Answer

|dw:1344353759006:dw|

turingtest · Answer

@3psilon let me know if you still don't get it...

3psilon · Answer

So you're factoring out the 3?

3psilon · Answer

Not sure how you go tto  3^(20+1)

turingtest · Answer

no, I am combining like terms
call$$(3^{20})=x$$we then have$$(3^{20})+(3^{20})+(3^{20})=x+x+x=3x$$sub back in what we know x is...$$3x=3(3^{20})$$now we use the property$$x^a\cdot x^b=x^{a+b}$$and get$$3(3^{20})=3^1\cdot3^{20}=3^{20+1}=3^{21} $$

3psilon · Answer

OHHHH

3psilon · Answer

Yes! I thought I got it last night, but then I saw this problem and was embarrassed to ask again. Thank you turing

turingtest · Answer

very welcome! please never be too embarrassed to ask

3psilon · Answer

I won't! You will see me more often! haahaha have a good one