có thể là -9 nữa nhá

12a - 7b = 45

==> a = 9 

==> b = 9

????????????

đề lạ thế

VD

A={1,2,3}

B={3,2,1}

=> A c B , B c A 

==> A = B

Khoanh tròn đáp án đúng

:1.We often read the instructions carefully in order to make ____ of the things we like best

A, meanings     B. models    C, copies     D. uses

2. You need to be ____ to follow eggshells carving because it may take two weeks to complete one shells.

A, careful      B, interested         C, fit               D, patient

3, if you choose sewing as your hobby , you will ____ your own clothes

A, do         B. make               C. take          D. get

1. He / now wear / face mask protect him / breathe / dust

=> He is wearing face mask protect him to breathe yo dust

2. Last year / my brother / work / engineer / printing factory

=> Last year my brother works an engineer in printing factory

3. Tìm lỗi sai : The doctor told her to sit down and asked what was the matter with her.

lỗi sai là dấu . câu phải đổi thành dấu chấm hỏi ???

còn 1 lổi nửa mà mk ko pik ^^ xl

chuẩn đó a ạ