Question

9x^2-6x-3=0 ;x^2+10x=24 ;25x^2-10x-8=0

Answer 1

9x^2-6x-3=0

delta1=(-6)^2-4*9*(-3)=36+108=144
x1=(6+12)/(2*9)=18/18=1
x2=(6-12)/(2*9)= -6/18 = -1/3

x^2+10x=24
x^2+10x-24=0

delta2=10^2-4*1*(-24)=100+96=196
x1=(-10+14)/(2*1)=4/2=2
x2=(-10-14)/(2*1)= -24/2 = -12

25x^2-10x-8=0

delta3=(-10)^2-4*25*(-8)=100+800=900
x1=(10+30)/(2*25)=40/50=4/5
x2=(10-30)/(2*25)= -20/50= -2/5

Answer 2

9x^2-6x-3=0
9x^2-9x+3x-3=0
9x(x-1)+3(x-1)=0
(x-1)(9x+3)=0
x=1 sau 9x+3=0
9x=-3
x=-1/3

x^2+10x=24
x^2+10x-24=0
x^2-2x+12x-24=0
x(x-2)+12(x-2)=0
(x-2)(x+12)=0
x=2 sau x=-12