a) [tex]e)x^2 + 19x + 16\\\\ =x^2+2.\frac{19}{2}x+(\frac{19}{2})^{2}-(\frac{19}{2})^2+16\\\\ =(x+\frac{19}{2})^{2}-\frac{297}{4}\\\\ =(x+\frac{19}{2}-\frac{căn 297}{2})+(x+\frac{19}{2}+\frac{căn 297}{2})[/tex] 2x^4 - x^2 -1
b) x^2 - 2x - 15
c) 4x^2 - 3x - 1
d) x^2 - 10x + 16
e) x^2 + 19x + 16
[tex]a, 2x^4 - x^2 -1=2x^4+x^2-2x^2-1\\\\ =x^2.(2x^2+1)-(2x^2+1)=(2x^2+1).(x-1).(x+1)[/tex]
[tex]b, x^2 - 2x - 15=x^2-5x+3x-15\\\\ =x.(x-5)+3.(x-5)=(x-5).(x+3)[/tex]
[tex]c, 4x^2 - 3x - 1=4x^2+x-4x-1\\\\ =x.(4x+1)-(4x+1)=(4x+1).(x-1)[/tex]
[tex]d,x^2 - 10x + 16=x^2-2x-8x+16\\\\ =x.(x-2)-8.(x-2)=(x-2).(x-8)[/tex]
[tex]e)x^2 + 19x + 16\\\\ =x^{2}+19x+(\frac{19}{4})^2-(\frac{19}{4})^2+16\\\\ =(x+\frac{19}{4})^2-(\frac{297}{4})^2\\\\ =...[/tex]