Odpowiedź:
Szczegółowe wyjaśnienie:
10.
a.
[tex]w(x)=x^4+6x^3-7x^2=x^2(x^2+6x-7)=x^2(x^2+7x-x-7)=\\=x^2[x(x+7)-(x+7)]=x*x*(x+7)(x-1)[/tex]
b.
w(x)=[tex]-\frac{1}{2} x^3+x^2-\frac{3}{2} x=-\frac{1}{2} x(x^2-2x+3)[/tex]
Δ<0 dalej nie da się rozłożyć
11.
[tex]w(x)=x^6-4x^4=x^4(x^2-4)=x^4(x-2)(x+2)[/tex]
[tex]w(x)=4x^4+8x^3+4x^2=4x^2(x^2+2x+1)=4x^2(x+1)^2[/tex]
12.
[tex]u(x)=2x^3-x^2+2x-1=x^2(2x-1)+(2x-1)=(x^2+1)(2x-1)[/tex]
Δ<0
[tex]u(x)=2x^3-4x^2+4x-2=2(x^3-1)-4x(x-1)=2(x-1)(x^2+x+1)-4x(x-1)=\\=2(x-1)(x^2+x+1-2x)=2(x-1)(x^2-x+1)[/tex]
13.
x(x+2)(-x-3)(3-x)=0
x₁=0 v x₂=-2 v x₃=-3 v x₄=3
Odp. C 2
14.
[tex](x^2+5x+6)(10-x)=0\\(x^2+3x+2x+6)(10-x)=0\\{[x(x+3)+2(x+3)](10-x)=0}\\(x+3)(x+2)(10-x)=0\\[/tex]
x₁=-3 v x₂=-2 v x₃=10
Odp. B -3
15.
[tex]x^5-2x^3=0\\x^3(x^2-2)=0\\x^3(x-\sqrt{2} )(x+\sqrt{2} )=0[/tex]
x₁=0 v x₂=√2 v x₃=-√2
16.
[tex]w(x)=2x^3-3x^2-6x+9=x^2(2x-3)-3(2x-3)=(2x-3)(x^2-3)=\\=(2x-3)(x-\sqrt{3} )(x+\sqrt{3} )[/tex]
[tex]x_1=\frac{3}{2}[/tex] v [tex]x_2=\sqrt{3}[/tex] v [tex]x_3=-\sqrt{3}[/tex]
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Odpowiedź:
Szczegółowe wyjaśnienie:
10.
a.
[tex]w(x)=x^4+6x^3-7x^2=x^2(x^2+6x-7)=x^2(x^2+7x-x-7)=\\=x^2[x(x+7)-(x+7)]=x*x*(x+7)(x-1)[/tex]
b.
w(x)=[tex]-\frac{1}{2} x^3+x^2-\frac{3}{2} x=-\frac{1}{2} x(x^2-2x+3)[/tex]
Δ<0 dalej nie da się rozłożyć
11.
a.
[tex]w(x)=x^6-4x^4=x^4(x^2-4)=x^4(x-2)(x+2)[/tex]
b.
[tex]w(x)=4x^4+8x^3+4x^2=4x^2(x^2+2x+1)=4x^2(x+1)^2[/tex]
12.
a.
[tex]u(x)=2x^3-x^2+2x-1=x^2(2x-1)+(2x-1)=(x^2+1)(2x-1)[/tex]
Δ<0
b.
[tex]u(x)=2x^3-4x^2+4x-2=2(x^3-1)-4x(x-1)=2(x-1)(x^2+x+1)-4x(x-1)=\\=2(x-1)(x^2+x+1-2x)=2(x-1)(x^2-x+1)[/tex]
Δ<0
13.
x(x+2)(-x-3)(3-x)=0
x₁=0 v x₂=-2 v x₃=-3 v x₄=3
Odp. C 2
14.
[tex](x^2+5x+6)(10-x)=0\\(x^2+3x+2x+6)(10-x)=0\\{[x(x+3)+2(x+3)](10-x)=0}\\(x+3)(x+2)(10-x)=0\\[/tex]
x₁=-3 v x₂=-2 v x₃=10
Odp. B -3
15.
[tex]x^5-2x^3=0\\x^3(x^2-2)=0\\x^3(x-\sqrt{2} )(x+\sqrt{2} )=0[/tex]
x₁=0 v x₂=√2 v x₃=-√2
16.
[tex]w(x)=2x^3-3x^2-6x+9=x^2(2x-3)-3(2x-3)=(2x-3)(x^2-3)=\\=(2x-3)(x-\sqrt{3} )(x+\sqrt{3} )[/tex]
[tex]x_1=\frac{3}{2}[/tex] v [tex]x_2=\sqrt{3}[/tex] v [tex]x_3=-\sqrt{3}[/tex]