Question

(x-2)(-x-1)=0
Помогите

Answer 1

(x - 2)(-x - 1) = 0,

х - 2 = 0,    -х - 1 = 0,

х1 = 2,        х2 = -1

Answer 2

(x-2)(-x-1)=0

-x²+2x-x+2=0

-x²+x+2=0 | ·(-1)

x²-x-2=0

X₁,₂= $\frac{1±\sqrt{1-4(-2)} }{2}$ = $\frac{1±\sqrt{9} }{2} = \frac{1±3}{2}$

X₁ = $\frac{1+3}{2} = \frac{4}{2} = 2$

X₂ = $\frac{1-3}{2} = \frac{-2}{2} = -1$