-3^4 tells you to take the number 3 and multiply it by itself 4 times.
-3^4 = -3 * 3 * 3 * 3
Ignoring the negative in front until the end.
= -81
(-3)^4 tells you to take the number -3 and multiply it by itself 4 times.
(-3)^4 = (-3) * (-3) * (-3) * (-3)
Which gives us a different result,
= 81
