Question

Special factorization
I know someone has helped me with this before, but I'm really stuck on how to attack these two problems

[(8x^3)/125]+[64/(y^3)]

X^2-8xy+16y^2-25

Answer 1

I am not sure what you want but

8 = 2^3
125 = 5^3

64 = 2^6 = 4^3


(2x/5)^3 + (4/y)^3

but a^3 + b^3 = (a+b)(a^2-ab+b^2)

(2x/5+4/y)(4x^2/25-8x/y+16/y^2)

Answer 2

maybe complete the square?

(x^2-8xy+16y^2) -16y^2 +16y^2-25

(x-4y)^2 - 5^2

(a-b)^2 = (a+b)(a-b)

(x-4y+5)(x-4y+5)

Answer 3

Is it not 8x/5y not 8x/y. I'm only basing this off of what you gave me

Answer 4

Yes, you are right

Answer 5

and in the second one a sign error

(x-4y+5)(x-4y-5)

Answer 6

Thank you sir!!! And thanks for being awake(unless you're not from the U.S)

Answer 7

You are welcome and I am from a fishing town north of Boston where we rise early.

Answer 8

Pretty darn early, and I'm 30 mins away from philly