Question

A )2x²+10x=0
B)x²+x(x-6)=0
C)x(x-3)-2(-3)=6
D)(x-2)²=4-9x

Answer 1

a) 2x²+10x=0
x(2x+10)=0
x'=0 2x+10=0
2x=-10
x"=-10/2 S={0,-5}
x"=-5


b)x²+x(x-6)=0
x²+x²-6x=0
2x²-6x=0
2x(x-3)=0 S={0,3}
2x=0 x-3=0
x'=0/2 x"=3
x'=0

c)x(x-3)-2(-3)=6
x²-3x+6=6
x²-3x+6-6=0
x²-3x=0 S={0,3}
x(x-3)=0
x'=0 x-3=0
x"=3


d)(x-2)²=4-9x
(x-2)(x-2)=4-9x
x²-4x+4=4-9x
x²-4x+4-4+9x=0
x²+5x=0
x(x+5)=0 S={0,-5}
x'=0 x+5=0
x"=-5