tập ước là j

- 1200= 2⁴.3.5²

- Ư(1200) = {1;-1;2;-2;3;-3;4;-4;5;-5;6;-6;8;-8;10;-1012;-12;15;-15;16;-16;20;-20;24;-24;25;-25; 40;-40;50;-50;75;-75 ;80;-80;100 ;-100;400 ;-400 ; 1200;-1200}

- 630 = 2.3².5.7 ( rùi bn tự suy ra Ư(630)  nha)

- 345 = 3.5.23

- 250 = 2.5³

- 75 = 3.5²

tập ước của 120 {1,2,3,4,5,6,8,10,12,15,16,20,24,25,30,40,48,50,60,75,80,100,120,150,200,240,400,600,1200

x + 630 = 630 + 1000

x + 630 = 1630

x          = 1630 - 630

x          = 1000

x + 630 = 630 + 1000

x + 630 = 1630

x          = 1630 - 630

x          = 1000

x + 630 = 630 + 1000

x + 630 = 1630

x = 1630 - 630

x = 1000

Mk nhanh nhất đó

**** mk nha 

\(-\left(-630\right)+915+\left(-630\right)+\left(-615\right)\)

\(=630+915-630-615\)

\(=915-615\)

\(=300\)

 -(-630)+915+(-630)+(-615)

= 630 + 915 - 630 - 615

= (630 - 630) + (915 - 615)

= 0 + 300

= 300

\(-\left(-630\right)+915+\left(-630\right)+\left(-615\right)\)

\(=630+915-630-615\)

\(=\left(630-630\right)+\left(915-615\right)\)

\(=0+300\)

\(=300\)

k) 4 x 113 x 25 - 5 x 112 x 20

= (4 x 25) x 113 - (5 x 20) x 112

= 100 x 113 - 100 x 112

= 100 x (113 - 112)

= 100

p) 1235 x 6789 x (630 - 315 x 2) : 1996

= 1235 x 6789 x (630 - 630) : 1996

= 1235 x 6789 x 0 : 1996

= 0

l) 54 x 113 + 45 x 113 + 113

= 113 (54 + 45 + 1)

= 113 x 100

= 11300

u) (500 x 9 - 250 x 18) x (1 + 2 + 3 + ... + 9)

= (2 x 250 x 9 - 250 x 2 x 9) x (1 +2 + 3 + ... + 9)

= 0 x (1 + 2 + 3 + ... + 9)

= 0

420 + x = 630

x = 630 - 420

x = 210

Vậy x = 210

K mk nha

Mk k lại

x=630-420

x=210

420+x=630

x=630-420

x=210

43,57 x 2,6 x ( 630 - 315 x 2 )

=43,57 x 2,6 x ( 630 - 630 )

=43,57 x 2,6 x 0

= 0

0

0

x + 630 = 7480

x = 7480 - 630

x= 6850

x+630=641+6839

x+630=7480

x=7480-630

x=       6850

x +630 = 641 +6839

x +630 = 7480

x = 7480 - 630 

x = 6850

x + 63 = 200 + 630

x + 63 = 830

x = 830 - 63

x = 767

x + 63 = 200 + 630

x + 63 =    830

x         = 830 - 63

x         =    767

x + 63 = 200 + 630

x + 63 = 830

x         = 830 - 63

x        = 767

x + 630 = 1218

        x  =  1218- 630 

        x = 588

x+630=586+632

=>x=586+632-630=588

586 ĐÚNG