c) (x+3)²-(x+1)(x-4)

=x²+6x+9-(x²-3x+4)

=x²+6x+9-x²+3x-4

=9x+5

sin⁴α+cos⁴α+2sin²α.cos²α

đúng nhé bạn

dt hình thang 

29x6,5=188,5(m)

Does she have to wear uniform at work ?

You should finish your homework quickly .

Shall we meet outside the movie theater.

They haven't to go out now

My brother has a short curly and black hair

We didn't arrived early enough to see that film

17. the doctor advise to take more exercise

18.Paul apologized to Susan for giving the wrong number.

19.Martin apologised to Angela for damaging her car

20. she reminded me not to forget to bring my passport with me the following day