Question

(x + 21) : 8 + 12 = 21

khi đầy đủ giúp mik nha ai nhanh mik tik

Answer 1

Giải:

( x + 21 ) : 8 + 12 = 21

( x + 21 ) : 8 = 21 -12

( x + 21 ) : 8 = 9

x + 21 = 9 . 8

x + 21 = 72

x = 72 - 21

x = 51

Vậy x = 51

Học tốt!!

Answer 2

(x+12):8=21-12

(x+12):8=9

x+12=9x8

x+12=72

x=72-12

x=60

Answer 3

(x + 21) : 8 + 12 = 21

=> ( x + 21 ) : 8 = 9 

=> x + 21 =72 

=> 72 - 21 = 51 

vậy x = 51

Answer 4

(x+21):8+12=21

(x+21):8=21-12

(x+21):8=9

x+21=9.8

x+21=72

     x=72-21

     x=51

Answer 5

nhầm

(x+21):8+12=21

(x+21):8=21-12

(x+21):8=9

x+21=8x9

x+21=72

x=72-21

x=51

Answer 6

x=51 mới đúng nha mk viết nhầm 21 thành 12

Answer 7

(x+21):8+12=21

(x+21):8      =9

 x+21          =9/8

 x                =9/8-21

x                 =-159/8

Answer 8

51 mới đúng 

Answer 9

\(\left(x+21\right):8+12=21\)

\(=\left(x+21\right):8=9\)

\(\Leftrightarrow x+21=72\)

\(\Leftrightarrow x=51\)

Answer 10

(x+21):8+12=21

=>(x+21):8=21-12

=>(x+21):8=9

=> x+21=8x9

=>x+21=72

=>x=72-21

=>x=51

Vậy x=51

Answer 11

Ta có: \(\left(x+21\right)\div8+12=21\)

\(\Leftrightarrow\left(x+21\right)\div8=9\)

\(\Leftrightarrow x+21=72\)

\(\Rightarrow x=51\)