Question

La exercitiul 9 vreau doar 1-2 exemple dar pe 10 il vreau complet dau 25 de puncte multumesc anticipat.

Answer 1

9)


a)3x²+9x=0

3x²+9x=3x•(x+3)

3x•(x+3)=0

3x=0=>x=0

x+3=0=>x=-3


b)x²+9x+8=0

x²+1x+8x+8=

x•(x+1)=

8•(x+1)=

(x+8)•(x+1)=0

x+8=0=>x=-8

x+1=0=>x=-1


d)x²+9x-10=0

x²-1x+10x-10=

x•(x-1)=

10•(x-1)=

(x+10)•(x+1)=0

x+10=0=>x=-10

x-1=0=>x=1


e)3x²+x=4

(3x²+x)-4=0

3x²-3x+4x-4=

3x•(x-1)=

4•(x-1)=

(3x+4)•(x-1)=

(x-1)•(3x+4)=0

x-1=0=>x=1

3x+4=0

3x=-4

$= > x = - \frac{4}{3} = - 1.333$