Tính nhanh $5^2; 6^2; {81}^4$

giúp em nhé hihhi
bài 4:chọn đáp án đúng
1. her...........room is next to the living room
A.sister's B.sisters'
2.It's the...........toy
A.boy's B.boy'
3.these are the.........pencil
A.boys's B.boy's
4.they're............shorts
A.Tom' B.Tom's
5.my ............... car was not expensive
A.parents' B.parents's
6.this is my ............book
A.brother B.brother's
7.my............ bedroom is next to the living room
A.sister B.sister's
8.this is my ..................... bike
A.brother's B.brothers

9.the....................room is upstairs
A.children B.children's
10.there is a TV in ............ bedroom
A. elena B.lena's
11................boat house look very strange
A.Mr green's B.Mr Greens'
12.My........ garden is full of beautiful flowers
A.grandparents' B.grandparents
13.Where is .............. laptop?
A. Nam B.Nam's
14...........house is big
A.Mai' B.Mai's

viết bài văn phân tích bài thơ thư của cha của tác giả nguyên hương

$\frac{2,5}{2}=\frac{50}{x}$ ???

tính đạo hàm y = $\frac{5x-2}{2x-5}$

tính đạo hàm y = -x³ + 3x² - 2