a. \(3x^4+4x^2+1=\left(3x^2+1\right)\left(x^2+1\right)\)
b. \(x^4+3x^2-4=\left(x^2-1\right)\left(x^2+4\right)\)
c. \(4x^4-37x^2+9=\left(x^2-9\right)\left(4x^2-1\right)\)
d. \(\left(x^2+x\right)^2+4\left(x^2+x\right)-12=x^4+2x^3+x^2+4x^2+4x-12=x^4+2x^3+5x^2+4x-12=\left(x-1\right)\left(x^3+3x^2+8x+12\right)=\left(x-1\right)\left(x+2\right)\left(x^2-x+6\right)\)
e. \(x\left(x+4\right)\left(x+6\right)\left(x+10\right)+128=x^4+20x^3+124x^2+240x+128=\left(x^2+10x+8\right)\left(x^2+10x+16\right)\)
a)3x^4+4x^2+1
= x2 (3x2 + 4)+1
b) x4+3x2-4
= x2 ( x2 + 3 )-4
c) 4x4-37x2+9
= x2 ( 4x2 - 37 ) + 9
d) (x2+x)2+4(x2+x)-12
= ( x2 + x )[( x2+x) + 4]-12
e) x.(x+4) (x+6) (x+10)+128
= x . (x + 2) (2+3+5)+128