Mình thấy đề đúng mà​.Ở số 3x là 3 nhân x viết tắt là 3.x

      3x-38=2³:2

=>  3.x-38=4

=>  3.x      =4+38

=>  3.x       =42

=>     x        =42:3

=>      x        =14

Con này không sai đâu bạn nhá!!!!!(^_^)

MI = MP/2 = (MN+NP)/2 = (3+5)/2 = 4 

có biết cái gì đâu mà làm!

yeu con cho 

(1): The weather                                                       (6): They are going to have a good lunch together

(2): staying                                                                (7): with

(3): Mr.Kien                                                               (8): they

(4): are                                                                      (9): evening

(5): washing                                                              (10): finish

Fill in each blank with the suitable word.

    Today is Sunday . The weather (1) is fine and warm. Mr Kien's family are staying(2) at home. They are working in the home now. Mr Kien is cleaning the doors and windows. Nam is helping Mr.Kien(3). Mrs Oanh and Hoa are (4) in the kitchen. Mrs Oanh is washing(5) the dishes. Hoa is cleaning the vegetables. They are cooking the lunch. They are going to have (6) a good lunch together. 

    Mr Kien's family are not free today.They are busy with(7) the housework, but they are very happy. They are going to finish the housework at half past eleven, then they (8) will have lunch. In the afternoon they are going to the park. In the evening (9) Nam and Hoa are going to finish(10) all the exercises before going to bed.

\(T=\left(a+b-c\right)-\left(b-a\right)-\left(a-b-c\right)\)

\(=a+b-c-b+a-a+b+c\)

\(=a+b\)

Vậy \(T=a+b\)

T = ( a + b - c ) - ( b - a )- ( a - b - c )

T = a + b - c - b + a - a + b + c

T =(a + a - a ) + ( b - b + b ) + ( -c + c )

T = a + b + 0

T = a + b

Vì x : 10 ; 15 đều dư 2 => x - 2 \(\in\)BC ( 10;15 )

Ta có :

10 = 2 . 5

15 = 3 . 5

=> BCNN ( 10 ; 15 ) = 2 . 3 . 5 = 30 

Mà BC ( 10 ; 15 ) = B ( 30 ) \(\in\){ 0 ; 30 ; 60 ; 90 ; 120 ; ... }

=> X - 2 \(\in\){ 0 ; 30 ; 60 ; 90 ; 120 ;.....}

     X \(\in\){ 2 ; 32 ; 62 ; 92 ; 120 ; ... }

Vì x < 100

=> X \(\in\){ 2 ; 32 ; 62 ; 92 }