(3x+3) : 3 - 21 = 315: 311
=> ( 3x+3) : 3 - 21 = 34
=> ( 3x+3) : 3 - 21 = 81
=> ( 3x+3) - 21 = 81 : 3
=> ( 3x+3) - 21 = 27
=> 3x+3 = 27 + 21
=> 3x+3 = 84
=> 3x = 84 - 3
=> 3x = 81
=> x = 81 : 3
=> x = 27
Vậy x = 27
\(\left(3x+3\right):3-21=3^{15}:3^{11}\)
\(\left(3x+3\right):3-21=3^4\)
\(\left(3x+3\right):3-21=81\)
\(\left(3x+3\right):3=81+21\)
\(\left(3x+3\right):3=102\)
\(\left(3x+3\right)=102\cdot3\)
\(3x+3=306\)
\(3x=306-3\)
\(3x=303\)
\(x=303:3\)
\(x=101\)
( 3x + 3 ) : 3 - 21 = 315 : 311
( 3x + 3 ) : 3 - 21 = 34
( 3x + 3 ) : 3 - 21 = 81
( 3x + 3 ) : 3 = 81 + 21
( 3x + 3 ) : 3 = 102
( 3x + 3 ) = 102 . 3
3x + 3 = 306
3x = 306 - 3
3x = 303
x = 303 : 3
x = 101
(3x+3):3-21=315:311
(3x+3):3-21 =34
(3x+3):3-21 =81
(3x+3):3 =81+21
(3x+3):3 =102
3x+3 =102x3
3x+3 =306
3x =306-3
3x =303
x =303:3
x =101
Chúc bạn thi tốt nhé!
