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

x+700=900-100

x+700=800

x        = 800-700

x         = 100

x+300=400+500

x+300=900

x       = 900-300 

x       = 600

x+100=900+300

x+100= 1200

x        = 1200 - 100

x       = 1100

x+700=900-100

x+700=800

x       =800-700

x       =100

x+300=400+500

x+300=900

x       =900-300

x       =600

x+100=900+300

x+100=1200

x      =1200-100

x      =1100

x + 700 = 900 - 100

x + 700 = 800

x = 800 - 700

x = 100

x + 300 = 400 + 500

x + 300 = 900

x = 900 - 300

x = 600

x + 100 = 900 + 300

x + 100 = 1200

x = 1200 - 100

x = 1100

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

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

\(x-\left[\frac{50x}{100}+\frac{25x}{200}\right]=11\frac{1}{4}\)

\(x-\left[\frac{50x\cdot2}{200}+\frac{25x}{200}\right]=11\frac{1}{4}\)

\(x-\left[\frac{100x}{200}+\frac{25x}{200}\right]=11\frac{1}{4}\)

\(x-\frac{125x}{200}=11\frac{1}{4}\)

\(\frac{200x}{200}-\frac{125x}{200}=11\frac{1}{4}\)

\(\frac{200x-125x}{200}=11\frac{1}{4}\)

\(\frac{75x}{200}=11\frac{1}{4}\)

\(\frac{3x}{8}=11\frac{1}{4}\)

\(3x=11\frac{1}{4}\cdot8\)

\(3x=90\)

\(x=30\)

Vậy x = 30

cảm ơn bn nhé

kb ko 

1200000000000

Học sinh nhẩm và ghi kết quả như sau:

200 x 2 = 400

200 x 4 = 800

100 x 5 = 500

300 x 2 =600

400 x 2 =800

500 x 1 =500

200 x 2 = 400          300 x 2 =600

200 x 4 =  800         400 x 2 =800

100 x 5 = 500          500 x 1 =500

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