5 . 8 - ( 9 + x ) = 20
40 - ( 9 + x ) = 20
9 + x = 40 - 20
9 + x = 20
x = 20 - 9
x = 11
Cách 2 :
5 . 8 - ( 9 + x ) = 20
40 - 9 - x = 20
31 - x = 20
x = 31 - 20
x = 11
\(5.8-\left(9+x\right)=20\)
\(\Leftrightarrow40-\left(9+x\right)=20\)
\(\Leftrightarrow40-9-x=20\)
\(\Leftrightarrow31-x=20\)
\(\Leftrightarrow x=31-20\)
\(\Leftrightarrow x=11\)
Vậy \(x=11\)
5.8-(9+x)=20
40-(9+x)=20
(9+x0)= 40- 20
9+x = 20
x = 20- 9
x = 11
Vậy x = 11
5.8-(9+x)=20
40-(9+x) =20
9+x = 40-20
9+x = 20
x = 20-9
x = 11
Vậy x=11
Chúc bạn học tốt!
5 x 8 - ( 9 + x ) = 20
40 - ( 9 + x ) = 20
9 + x = 40- 20
9 + x =20
x = 20 - 9
x = 11
⚠
