Question

(25-4x²)(x²-36)=0

x³-6x²+8x=0

x³-2x²-4x+8=0

pomozecie mi?proszee

Answer 1

zad.1

(25-4x^{2})(x^{2}-36)=0

(5-2x)(5+2x)(x-6)(x+6)=0

 

5-2x=0    lub 5+2x=0   lub x-6=0   lub x+6=0

 -2x=-5      ^     2x=-5      ^    x=6       ^     x=-6

    x=5/2             x=-5/2         x=6             x=-6

 

zad.2

 

x³-6x²+8x=0

x³-4x²-2x²+8x=0   (w zadaniu rozbiliśmy -6x²=-4x²-2x²)

x²(x-4)-2x(x-4)=0

(x-4)(x²-2x)=0

x(x-2)(x-4)=0

 

x=0    lub  x-2=0      lub x-4=0

                  x=2          ^     x=4

 

 

zad.3.

 

x³-2x²-4x+8=0

x²(x-2)-4(x-2)=0

(x-2)(x²-4)=0

(x-2)(x-2)(x+2)=0

 

x-2=0     lub x+2=0

   x=2        ^       x=-2