What makes me happy irl is nothing really, I only exist to make others happy
Hahah PHILSWIFT I answered first
Answer: 3 mi/h
Step-by-step explanation:
Here we have to find the speed
at which Sarah walks to school, knowing the distance
she has walked and the time
she expends.
So, in this case we can use the following equation:

Where:


Solving:

This is Sarah's speed
I'm assuming you meant to write a^4 = 625.
If that is the case, then note how 625 = 25^2, and how a^4 is the same as (a^2)^2
So we go from this
a^4 = 625
to this
(a^2)^2 = 25^2
Apply the square root to both sides and you'll end up with: a^2 = 25
From here, apply the square root again to end up with the final answer: a = 5 or a = -5
As a check:
a^4 = (-5)^4 = (-5)*(-5)*(-5)*(-5) = 25*25 = 625
a^4 = (5)^4 = (5)*(5)*(5)*(5) = 25*25 = 625
Both values of 'a' work out