oblicz pierwiastki wielomianu a) W(x)= x3+2x2-5x-10 b) P(x)= x4-2x3-7x2+20x-12 w słupku poproszę

a) W(x)=x³+2x²-5x-10 W(x)=0 x³+2x²-5x-10=0 x²(x+2)-5(x+2)=0 (x²-5)(x+2)=0 (x-√5)(x+√5)(x+2)=0 x-√5=0  lub  x+√5=0  lub  x+2=0  x=√5           x=-√5          x=-2 ------------------------------------ b) P(x)=x⁴-2x³-7x²+20x-12 P(x)=0 x⁴-2x³-7x²+20x-12=0 x⁴-2x³-7x²+14x+6x-12=0 x³(x-2)-7x(x-2)+6(x-2)=0 (x³-7x+6)(x-2)=0 (x³-x-6x+6)(x-2)=0 [x(x²-1)-6(x-1)](x-2)=0 [x(x-1)(x+1)-6(x-1)](x-2)=0 {(x-1)[x(x+1)-6]}(x-2)=0 (x-1)(x²+x-6)(x-2)=0 x-1=0  lub  x-2=0  lub  x²+x-6=0  x=1           x=2          x=-2  x=3 --- x²+x-6=0 Δ=b²-4ac1²-4*1*(-6)=1+24=25 √Δ=5 x₁=[-b-√Δ]/2a=[1-5]/2=-2 x₂=[-b+√Δ]/2a=[1+5]/2=3