25x^2 + 13x -24x^2-15-3x+12
= x^2 +10x-3
4) 4x^2 +20= 4(x^2 +5 )
18x^3 -8x^2+4x= 2x( 9x^3 - 4x+2)
5(x-3)+x(x-3) = (x-3)(5 +x)
5) x^16 -1 = (x^8-1)(x^8+1) = (x^4-1)(x^4+1)(x^8+1)= (x^2-1)(x^2+1)(x^4+1)(x^8+1)= (x-1)(x+1)(x^2+1)(x^4+1)(x^8+1) 5 factori
