Question

va rog frumos faceți acest exercițiu va dau 35 de puncte

Answer 1

a)(x+3)(x-4)=-12=>x^2+3x-4x-12=-12=>x^2-x=0=>x(x-1)=0 =>x1=0 x2=1(Adica x-1=0=>x=1)

c)(3x-1)^2-1=0=>9x^2-2*1*3*x+1-1=0=>9x^2-6x=0=>x(9x-6)=0 x1=0 x2=6/9=2/3

e)3x(2x+3)-2x(x+4,5)=2=>6x^2+9x-2x^2-9x=2=>4x^2=2=>x^2=2/4=>x^2=1/2=>x1=+radical(1/2)=+1/radical(2) x2=-1/radical(2)

g)(x-1)(x+1)=2(x^2-3)=>x^2-1=2x^2-6=>x^2-2x^2-1+6=0=>-x^2+5=0=>5=x^2=>x1=+radical(5) x2=-radical(5)

b)5x+(2x+1)(x-3)=0=>5x+2x^2+x-6x-3=0=>2x^2+6x-6x-3=0=>2x^2=3=>x^2=3/2 => x1=+radical(1,5) x2=-radical(1,5)

d)x^2-5=(x+5)(2x-1)=>x^2-5=2x^2-x+10x-5=>0=2x^2-x^2+9x=>x^2+9x=0=>x(x+9)=0=>x1=0 x2=-9

f) 18-(x-5)(x-4)=-2=>18+(5-x)(x-4)=-2=>18+2-x^2+5x+4x-20=0=>-x^2+9x=0=>x(9-x)=0 =>x1=0 x2=9