-6 to the 5th means -6 times itself 5 times PEMDAS do the exponents first (-6)^5=(-6)(-6)(-6)(-6)(-6)=-7776
one shortcut is to recognize that -6=-1 times 6 so (-6)(-6)(-6)(-6)(-6)=(-1)(-1)(-1)(-1)(-1)(6)(6)(6)(6)(6) and remember that odd number of negatives is negative (since neagtive times positive=negative and negative times negative=positive)
