basically, when multiplying numbers or placeholders with the same base, just add the exponents
or
[tex](x^m)(x^n)=x^{m+n}[/tex]
just add the exponents, ONLY IF THE BASE IS THE SAME
like
2^3 times 2^4=2^(3+4)
but you can't do
2^4 times 4^2
but you can make it into
2^4 times 2^4=2^8
add exponents