3.a) = (12[tex] x^{2} [/tex]-15x-4x-5)-(12[tex] x^{2} [/tex]+30x-22x-55)=
12[tex] x^{2} [/tex]-11x-5 -12[tex] x^{2} [/tex]-8x+55= 50 -18x
b) = 2x[4[tex] x^{2} [/tex]-([tex] x^{2} [/tex]-3x+2x-6)] -5[tex] x^{3} [/tex]+15x=
2x(4[tex] x^{2} [/tex]-[tex] x^{2} [/tex]+x+6 ) -5[tex] x^{3} [/tex]+15x =
6[tex] x^{3} [/tex]+2[tex] x^{2} [/tex]+12x-5[tex] x^{3} [/tex]+15x = [tex] x^{3} +2 x^{2} [/tex]+27x =x([tex] x^{2} [/tex][tex]+2x+27)[/tex]
c) = (x+1)(3x+6-2x+2)-4x-8= (x+1) ( x+8) -4x-8 = [tex] x^{2} [/tex]+8x+x+8 -4x-8 =
[tex] x^{2} [/tex]+4x = x(x+4)
d) =(x-2)(4x+20 -3x -18)-[tex] x^{2} [/tex]+4x =(x-2)(x+2) -[tex] x^{2} [/tex]+4x = [tex] x^{2} +2x-2x-4- x^{2} +4x=4x-4=4(x-1)[/tex]
4a) = 8[tex] x^{3} -12 x^{2} -12x+4-2 x^{3} +6 x^{2} -8x-20 x^{3} +30 x^{2} -30x = -14 x^{3} +[/tex][tex]24 x^{2} -50x+4[/tex]
la 4 B se vede neclar si nu pot rezolva
