1, is-3
2, are-4
3,am-1
4,have PE lessons-6
5,is-2
6,am not-5

Bài 5 ở đâu vậy ạ?

a)2x²-7x-2x²-2x=7

-9x=7

x=-7/9

b)3x²+24x-x²-2x²-2x=2

22x=2

x=1/11

c: \(3x\left(x-7\right)-2\left(x-7\right)=0\)

\(\Leftrightarrow\left(x-7\right)\left(3x-2\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}x=7\\x=\dfrac{2}{3}\end{matrix}\right.\)

d: \(7x^2-28=0\)

\(\Leftrightarrow\left(x-2\right)\left(x+2\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}x=2\\x=-2\end{matrix}\right.\)

Bài 1: 

a: =8xy/2x=4y

b: \(=\dfrac{4x-1-7x+1}{3x^2y}=\dfrac{-3x}{3x^2y}=\dfrac{-1}{xy}\)

c: \(=\dfrac{3x-x+6}{2x\left(x+3\right)}=\dfrac{2\left(x+3\right)}{2x\left(x+3\right)}=\dfrac{1}{x}\)

e: \(=\dfrac{5\left(x+2\right)}{4\left(x-2\right)}\cdot\dfrac{-2\left(x-2\right)}{x+2}=\dfrac{-10}{4}=-\dfrac{5}{2}\)

câu 3 bài 1: = (x-y)(y-1)

2/

a/

\(\dfrac{4n+2}{n+1}=\dfrac{4n+4-2}{n+1}=\dfrac{4\left(n+1\right)-2}{n+1}=4-\dfrac{2}{n+1}\)

\(\Rightarrow4n+2⋮n+1\) Khi \(n+1=\left\{-2;-1;1;2\right\}\Rightarrow n=\left\{-3;-2;0;1\right\}\)

b/

\(\Rightarrow a+2=\dfrac{8}{b-1}\left(b\ne1\right)\) (1)

a nguyên => a+2 nguyên \(\Rightarrow8⋮\left(b-1\right)\)

\(\Rightarrow b-1=\left\{-8;-4;-2;-1;1;2;4;8\right\}\)

\(\Rightarrow b=\left\{-7;-3;-1;0;2;3;5;9\right\}\) Thay các giá trị của b vào (1) để tìm a

3/

Gọi số tiền mẹ cho Chi là A \(\Rightarrow100000\le A\le200000\)

Nếu bớt số tiền mẹ cho Chi đi 5000 đồng thì 

\(A-5000⋮15000;A-5000⋮8000\)

\(\Rightarrow A-5000=UC\left(8000;15000\right)\) Và \(95000\le A-5000\le195000\)

\(\Rightarrow A-5000=120000\Rightarrow A=125000\)