\(\left(x-2\right)\left(x^2+2x+4\right)-x\left(x-3\right)\left(x+3\right)=10\\ \Leftrightarrow x^3-8-x\left(x^2-9\right)=10\\ \Leftrightarrow x^3-8-x^3-9x=10\\ \Leftrightarrow-9x=18\\ \Leftrightarrow x=-2\)

x=2

(x−2)(x2+2x+4)−x(x−3)(x+3)=10⇔x3−8−x(x2−9)=10⇔x3−8−x3−9x=10⇔−9x=18⇔x=−2

9/10

9/10

\(\dfrac{9}{10}\)

= 60 + 288 - 152

= 348 - 152

= 196

196 nha bạn

196 uy tín

\(A=x^2-4x+9=\left(x-2\right)^2+5\ge5\forall x\)

Dấu '=' xảy ra khi x=2

\(B=x^2-x+1=\left(x-\dfrac{1}{2}\right)^2+\dfrac{3}{4}\ge\dfrac{3}{4}\forall x\)

Dấu '=' xảy ra khi \(x=\dfrac{1}{2}\)

Bằng 60 nha 

200+x=130+120

200+x=250

x=250-200

x=50

x=60

minh minh lại

Bài 1: 

\(A=x^2+6x+9+x^2-10x+25\)

\(=2x^2+4x+34\)

\(=2\left(x^2+2x+17\right)\)

\(=2\left(x+1\right)^2+32>=32\forall x\)

Dấu '=' xảy ra khi x=-1

\(\dfrac{1}{2}x=\dfrac{-3}{10}-\dfrac{3}{4}\)

\(\dfrac{1}{2}x=\dfrac{-21}{20}\)

\(x=\dfrac{-21}{20}:\dfrac{1}{2}\)

\(x=\dfrac{-21}{10}\)

`1 / 2 x + 3 / 4 = [-3] / 10`

`1 / 2 x = [-3] / 10 - 3 / 4`

`1 / 2 x = [-21] / 20`

`x = [-21] / 20 : 1 / 2`

`x = [-21] / 10`

\(\Leftrightarrow\dfrac{1}{2}x=-\dfrac{3}{10}-\dfrac{3}{4}\)

\(\Leftrightarrow\dfrac{1}{2}x=-\dfrac{21}{20}\)

\(\Leftrightarrow x=-\dfrac{21}{10}\)

Bài 2 : 

a, \(x^2-4x+4+1=\left(x-2\right)^2+1\ge1\)

Dấu ''='' xảy ra khi x = 2 

b, Ta có \(\left(x+1\right)^2+10\ge10\Rightarrow\dfrac{-100}{\left(x+1\right)^2+10}\ge-\dfrac{100}{10}=-10\)

Dấu ''='' xảy ra khi x = -1 

 Bài 1 : 

a, Ta có \(A\left(x\right)=x^2-4x+4=0\Leftrightarrow\left(x-2\right)^2=0\Leftrightarrow x=2\)

b, \(B\left(x\right)=x^2\left(2x+1\right)+\left(2x+1\right)=\left(x^2+1>0\right)\left(2x+1\right)=0\Leftrightarrow x=-\dfrac{1}{2}\)

c, \(C\left(x\right)=\left|2x-3\right|=\dfrac{1}{3}\Leftrightarrow\left[{}\begin{matrix}2x=\dfrac{1}{3}+3=\dfrac{10}{3}\\2x=-\dfrac{1}{3}+3=\dfrac{8}{3}\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{5}{3}\\x=\dfrac{4}{3}\end{matrix}\right.\)