400 + 300 = 100 + 500 + x

700 = 600 + x

x = 700 - 600

x = 100 

 400 + 300 = 100 + 500 + x

700           = 600 + x

x              = 700 - 600 

x             = 100

\(400+300=100+500+x\)

              \(700=600+x\)

                   \(x=700-600\)

                   \(x=100\)

X x 100 + X x 200 + X x 300 + X x 400 + X x 500 + X x 512 = 2012

X x (100 + 200 + 300 + 400 + 500 + 512) = 2012

X x 2012 = 2012

        X    = 2012 : 2012

        X    = 1

thanks.

X * 100 + X* 200 + X * 300 + X * 400 + X * 500 + X * 512 = 2012

                        X * (100 + 200 + 300 + 400 + 500 + 512) = 2012

                                                                      X * 2012 = 2012

                                                                                X = 2012 : 2012

                                                                                X = 1

Vậy X bằng 1

X x 100 + X x 200 + X x 300 + X x 400 + X x 500 + X x 512 = 2012

X x ( 100 + 200 + 300 + 400 + 500 + 512 ) = 2012

X x 2012 = 2012

X = 2012 : 2012

X = 1

500 + x = 100 + 500

500 + x = 600

          x = 600 - 500

          x = 1001

300 - x = 300 + 200

300 - x = 500

         x = 300 - 500

         x = -200

400 - x = 200 + 400

400 - x = 600

         x = 400 - 600

         x = -200

k mk nha mk k l

ại ^_^

500 + 100 = 100 + 500

300 + 200 =  300 + 200

400 + 200  = 200 + 400

500+x=100+500

vay x =100

300-x=300+200

vay x= - 200

400-x=200+400

vay x= -200

b) 200 x 4 = .800.....              300 x 2 = ..600....

200 x 2 = .400.....             300 x 3 = ...900...

400 x 2 = ...800...             500 x 1 = ..500....

100 x 4 = ..400....             100 x 3 = .300.....

800

400

800

400

600

900

500

300

ai giúp mình với

x + 100 = 200 - 300

x + 100 = - 100

          x = 100 - 100

          x = 0

x - 300 = 400 - 500

x - 300 = -100

        x = -100 + 300

        x = 200

k mik mik k lại

x + 100 = 200 - 300

x + 100 = -100

x = -100 - 100

x = -200

x - 300 = 400 - 500

x - 300 = -100

x = -100 + 300

x = 200 

1 bang-200

2bang200

\(A=|x+100|+|x+200|+|x+300|+|x+400|+2011\)

\(\ge|x+100+x+200+x+300+x+400|+2011\)

\(=|4x+1000|+2011\)

Dấu bằng xảy ra khi và chỉ khi \(4x+1000=0\Leftrightarrow x=-250\)

=> Min A= 2011

\(\left|x+100\right|+\left|x+200\right|+\left|x+300\right|+\left|x+400\right|+2011\ge\left|x+100+x+200+x+300+x+400\right|+2011=\left|4x+\left(100+200+300+400\right)\right|+2011\)\(\Rightarrow\left|x+100\right|+\left|x+200\right|+\left|x+300\right|+\left|x+400\right|\ge\left|4x+1000\right|+2011\)

\(\Rightarrow A_{Min}=2011\Leftrightarrow\left|4x+1000\right|=0\Leftrightarrow4x+1000=0\Leftrightarrow4x=-1000\Leftrightarrow x=-250\)

\(A=\left|x+100\right|+\left|x+200\right|+\left|x+300\right|+\left|x+400\right|+2011\)

\(\Leftrightarrow A\ge\left|x+100+x+200+x+300+x+400\right|+2011=\left|4x+1000\right|+2011\ge2011\)

Dấu '' = '' xảy ra 

\(\Leftrightarrow4x+1000=0\)

\(\Leftrightarrow4x=-1000\)

\(\Leftrightarrow x=-250\)

Vậy Min A = 2011 <=> x = -250

X-100=200+300+400

X-100=500+400

X-100=900

X=900+100

X=1000

x - 100  = 200+300+400

x - 100  = 900

x          =900+100

x          =1000

x - 100=200+300+400

x -100=900

x=900+100

x=1000

x - 100 = 200 + 900

x - 100 = 1100

x         = 1100 + 100

x         = 1200

x + 100 = 300 - 400

x + 100 = - 100

x          = - 100 - 100

x          = - 200

x+100=200+900

x+100=1000

x=1000-100

x=900

x+100=300-400

x+100=-100

x=-100-100

x=-200

X-100=200+900

X-100=1100

X       =1100+100

X       =1200

x - 300 = 400 - 100 - 100

x - 300 = 200

x = 200 + 300

x = 500.

x = 500 nhé bạn

x = 500