`B`

`=> x-3=5x-3`

`=> 4x=0`

`=> x=0`

`a) S=axxa`

`b) S=25xx25=625(m^2)`

Chiều rộng là:

`120:3/2=80(m)`

Diện tích là:

`120xx80=9600(m^2)`

Diện tích còn lại:

`9600xx(1-3/5)=3840(m^2)`

a) `=3/2 xx((3+4)/7)=3/2 xx1=3/2`

b) `=17/5 xx11/7 +12/35=(187+12)/35=199/35`

`=448-9+8=447`

`=5^4 +6^4 -26=1895`

Mary told Peter that she has brought the book back to him the previous day.

They told me they would be waiting for me if I was late.

thiếu : 2 ở sau kìa