Question

(x 4 + 5x 2 - 36)(2x 2 + 9x - 5) = 0

Answer 1

(x⁴+5x²-36)(2x²+9x-5)=0

either (x⁴+5x²-36) =0 or (2x²+9x-5)=0

case 1 :

   (x⁴+5x²-36) =0

⇒ x⁴-4x²+9x²-36 =0

⇒ x²(x²-4)+9(x²-4) = 0

⇒ (x²-4)(x²+9) = 0

here also one of them is zero...

case 1:

⇒ x²-4 = 0

⇒ (x+2)(x-2) = 0

from here x=2 or x= -2

case 2:

⇒ x²+9 =0

⇒ x² = -9

⇒ x = √-9

from here x=√-9

case 2:

(2x²+9x-5)=0

⇒ 2x² - x + 10x -5 =0

⇒ x(2x-1)+5(2x-1) = 0

⇒ (x+5)(2x-1) = 0

from here x = -5 or 1/2

so , x = 2 or -2 or √-9 or -5 or 1/2

hope it helps you...

^_^