Question

Factorize x^4-12x^2-64=0

Answer 1

64 = 8^2 right?

Answer 2

middle term breaking

Answer 3

breaking 12x^2

Answer 4

(x^2-16)(x^2+4)

Answer 5

ok .. :
\[\large{x^4+4x^2-16x^2-64=0}\] right?

Answer 6

absolutely right

Answer 7

then factorize it again

Answer 8

ok now ..
\[\large{x^2(x^2+4)-16x^2-64=0}\] right?

Answer 9

(x^2-16)(x^2+4)

Answer 10

(x^2-16)(x^2+4)= (x-4)(x+4)(x^2+4)

Answer 11

right :
\[\large{(a^2-b^2)=(a+b)(a-b)}\]

Answer 12

\[\large{x^2-4^2=(x+4)(x-4)}\]

Answer 13

x=+4,-4

Answer 14

the formula is right but i need to solve this without formula

Answer 15

hoe do you know that????? x=+4,-4

Answer 16

x2=16
squaring
x=+4,-4

Answer 17

then after that the hard part

Answer 18

using x+4=0

Answer 19

sorry x2+4=0

Answer 20

x^2=-4
squaring
x=+2i,-2i

Answer 21

you mean x^2+4=0

Answer 22

yeah

Answer 23

its done ok fine thanks for help every body