Question

Giải phương trình: x³+x+10=0

Answer 1

\(x^3+x+10=0\)

\(\Leftrightarrow x^3-2x^2+5x+2x^2-4x+10=0\)

\(\Leftrightarrow x\left(x^2-2x+5\right)+2\left(x^2-2x+5\right)=0\)

\(\Leftrightarrow\left(x+2\right)\left(x^2-2x+5\right)=0\)

\(\Leftrightarrow\left[\begin{array}{nghiempt}x+2=0\\x^2-2x+5=0\end{array}\right.\)\(\Leftrightarrow\left[\begin{array}{nghiempt}x+2=0\\\left(x^2-2x+1\right)+4=0\end{array}\right.\)

\(\Leftrightarrow\left[\begin{array}{nghiempt}x=-2\\\left(x-1\right)^2+4>0\left(loai\right)\end{array}\right.\)

Vậy x=-2

 

Answer 2

x³+x+10=0

=>x³+x= -10

<=> x(x²+1)= -10

Ta xét: 2.5= 10

=>x=2

 

Answer 3

x³ + x+10=0

=>x³+x= -10

<=>x(x²+1)= -10

Ta xét: -2.5 = -10

=>x= -2

Answer 4

máy tính bấm giải pt đê