You can write 15,409 like this 10000+5000+400+9 and like this fifteen thousand-four hundred nine
Answer:
64y² - 81
Step-by-step explanation:
(8y +9)(8y - 9)
64y² - 72y + 72y - 81
64y² - 81
Oh wait a minute i have to write this down
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
