x + 300 = 1000

x = 1000 - 300

x = 700 nhé bạn

x+500-200=1000

=> x+300=1000

=>x       = 1000-300

=>x      = 700

vậy: x=700

ai tk mk, tk lại.

x+500+200=9000-1000

x+(500+200)=8000

x+700=8000

x=8000-700

x=7300

x+500+200=9000-1000

x+700       =8000

           x   =8000-700

           x=7300

k mình nha

a) x . x . x = 125

x³ =125

x³ = 5³

= > x = 5

b) ( x + 500 ) = 1000 - 200 . 2

x + 500 = 1000 - 400

x + 500 = 600

x = 600 - 500

x = 100

 a] = -5300

b)= -3204 

nha

100-200-300-400-500-600-700-800-900-1000=-5300

1000+299-1345-234-345-456-567-678-789-89=-3204

-500

nha

Các bạn k mình đi 

400+400=800

500+500=1000

600+600=1200

700+700=1400

800+800=1600

900=900=1800

1000+1000=2000

Mình đầu nhé!

400+400=800

500+500=1000

600+600=1200

700+700=1400

800+800=1600

900+900=1800

1000+1000=2000

=1000000

k mk nha 

mk k bn rùi đó

200 . 1000 + 800 . 1000

= 200 000 + 800 000

= 1 000 000

1-1/2+1/3-1/4+......-1/1000 

=(1+1/3+1/5+......+1/999)-(1/2+1/4+.......+1/1000) 

=(1+1/2+1/3+1/4+.....+1/1000)-2(1/2+1/4+.......+1/1000) 

=(1+1/2+1/3+.........+1/1000)-(1+1/2+.....+1/500) 

=1/501 +1/502+1/503+.....+1/1000 ; 

mat khác: 

500-500/501-501/502-.....-999/1000 

=(1-500/501)+(1-501/502)+.....+(1-999/1000)=1/501+1/502+....+1/1000  

=>D=1