Question

Descompuneti in factori:
x²+15x+56=
x²-9x-22=
x²-15x-100=
x²-23x-50=
x²+11x-26=
x²+16x-80=
x²+19x-20=
3x³+2x²-3x-2=

Answer 1

x²+15x+56= x²+7x+8x+56=x(x+7)+8(x+7)=(x+7)(x+8) ;
x²- 9x - 22 = x² +2x-11x - 22 = x(x+2)-11(x+2)=(x+2)(x-11) ; 
x²-15x-100= x²+5x-20x-100 = x(x+5)-20(x+5)=(x+5)(x-20) ;
x²-23x-50  = x² +2x-25x -50 =x(x+2) -25(x+2) = (x+2)(x-25) ;
x²+11x-26 = x² - 2x+13x-26 = x(x-2) +13(x-2) = (x-2)(x+13) ;
x²+16x-80 = x²+4x -20x -80 = x(x+4) - 20(x+4) = (x+4)(x-20) ;
x²+19x-20 = x² +x -20x-20 = x(x+1) -20(x+1) = (x+1)(x-20) ;
3x³+2x²-3x-2=3x³-3x+2x²-2=3x(x²-1)+2(x²-1)=(x²-1)(3x+2)=(x-1)(x+1)(3x+2)