a) -) Mai doesn't plays badminton after school
    ?) Does Mai play badminton after school?
b) -) She doesn't you out at the moment
    ?) Does she you out at the moment?
c) -) We don't after have a picnic on weekend
   ?) Do you after have a picnic on weekend?
d) -) The student aren't sitting in class
   ?) Are student sitting in class?
e) -) I can't play giutar
    ?) Can you play giutar?

Bạn ơi đề bài đáng ra là chuyển các câu sau sang phủ định và nghi vấn chứ
phays=plays

A) Mai don't play badminton after school

    Is Mai play badminton after school ?

B) She you out not at the moment

    Are you she out at the moment ?

C) We not after have a picnic on weekend

    Are we after have picnic on weekend ?

D) The student not are sitting in class

    Is student sitting in class ?

E) I can't play giutar

   Can I play giutar ?

X-1=10

X=   10-1=9

TH1: 1 \(\ge\)0 => x \(\ge\)1

x - 1 = 2x - 5

x - 2x = -5 + 1

-x = -4

x = 4 ( nhan )

TH2 : x - 1 < 0 => x < 1

-(x-1) = 2x - 5

-x+ 1 = 2x - 5

-x - 2x = -5 - 1

-3x = -6

=> x = 2 ( loai )

Vay x = 4

Ta có : 3x=2y=2y

=> x/2=y/3

=>x/10=y/15 (1)

2y=5z

=>y/5=z/2

=>y/15=z/6(2)

Từ 1 và 2 =>x/10=y/15=z/6

Tự giải

Ta có : \(3x=2y\Rightarrow x=\frac{2y}{3}\)(1)

            \(2y=5z\Rightarrow z=\frac{2y}{5}\)(2)

Thay (1) và (2) vào biểu thức x - y + z = 32 ; ta được: 

\(\frac{2y}{3}-y+\frac{2y}{5}=32\Rightarrow10y-15y+6y=480\Rightarrow y=480\)

Với \(y=480\Rightarrow x=\frac{2.480}{3}=320;z=\frac{2.480}{5}=192\)

KL :