2020/2021<1

2021/2022<1

2022/2023<1

2023/2020=1+1/2020+1/2020+1/2020>1+1/2021+1/2022+1/2023

=>B>2020/2021+2021/2022+2022/2023+1/2021+1/2022+1/2023+1=4

(x;y)=(0;0);(2;2)

a) y x 5 = 1948 + 247

y x 5 = 2195

y = 2195 : 5

y = 439

b) y : 3 = 190 - 90

y : 3 = 100

y = 100 x 3

y = 300

c) y - 8357 = 3829 x 2

y - 8357 = 7658

y = 7658 + 8357

y = 16 015

d) y x 8 = 182 x 4

y x 8 = 728

y = 728 : 8

y = 91

a) y x 5 = 1948 + 247

y x 5 = 2195

y = 2195 :5

y = 439

b) y : 3 = 190 - 90

y : 3 = 100

y = 100 x 3

y = 300

c) y - 8357 = 3829 x 2

y - 8357 = 7658

y = 7658 + 8357

y = 16015

d) y x 8 = 182 x 4

y x 8 = 728

y = 728 : 8

y = 91

Ta có \(|x-y+3|\ge0\forall x,y\)

\(2015\left(2y-3\right)^{2016}\ge0\forall y\)

\(\Rightarrow\hept{\begin{cases}|x-y+3|\ge0\\2015.\left(2y-3\right)^{2016}\ge0\end{cases}}\)

\(\Leftrightarrow\hept{\begin{cases}x-y+3=0\\\left(2y-3\right)^{2016}=0\end{cases}}\)

\(\Leftrightarrow\hept{\begin{cases}x-y+3=0\\2y-3=0\end{cases}}\)

\(\Leftrightarrow\hept{\begin{cases}x-y+3=0\\2y=3\end{cases}}\)

\(\Leftrightarrow\hept{\begin{cases}x-y+3=0\\y=\frac{3}{2}\end{cases}}\)

Bạn thay vào tìm x

Mik cũng hok Toán 2

x.(y+3)-y=-2

\(\Rightarrow\)x.( y + 3 ) = y - 2 

\(\Rightarrow\)xy + 3x = y - 2

 \(\Rightarrow\) y( x - 1 ) + 3( x - 1 ) + 5 = 0 

\(\Rightarrow\)y( x - 1 ) + 3( x - 1 ) = -5

\(\Rightarrow\)( y + 3 )( x - 1 ) = -5

\(\Rightarrow\)( y + 3 )( x - 1 ) \(\in\)Ư(-5) = { \(\pm1;\pm5\)}

Ta có bảng sau :

ta có x-3=y.(x-2)

     < =>x=y(x+2)+3

     <=> x=xy+2y+3

            x-xy-2y=3

           =>(1-y)x-2y=3

suy ra y=0 hoặc y=1

-Nếu y=0 thì x thuộc N=>1-y=1-0=1=>1x-2.0=3=>x-0=3=>x=3

-Nếu y=1 thì 1-1=0=>0.x-2.1=3=>0-2=3=>trường hợp này vô lý

Vậy x=3,y=0