Question

PLEASE HELP and explain
FACTOR
y^4-81

Answer 1

so, y^4 - 81 = (....)^2 - (....)^2

Answer 2

y and 9?

Answer 3

y^2 not be y^4, but right 9^2=81

Answer 4

so what do you do next

Answer 5

it should be
y^4 - 81 = (y^2)^2 - (9)^2
next use the property :
a^2 - b^2 = (a+b)(a-b)

Answer 6

ok i think i got it, how about 6a^4+13a^2-5

Answer 7

show ur answer

Answer 8

(y^2+9)(y-3)(y+3)

Answer 9

ok, correct...

Answer 10

for the 2nd question :
6a^4+13a^2-5 = (2a^2+5)(3a^2-1)
bonus for u :)