\(\left(y-\frac{2}{5}\right):\frac{4}{3}=\frac{3}{8}\)

\(y-\frac{2}{5}=\frac{3}{8}.\frac{4}{3}\)

\(y-\frac{2}{5}=\frac{1}{2}\)

\(y=\frac{1}{2}+\frac{2}{5}\)

\(\Rightarrow y=\frac{9}{10}\)

\(y.\frac{5}{6}=\frac{1}{4}+\frac{1}{3}\)

\(y.\frac{5}{6}=\frac{7}{12}\)

\(y=\frac{7}{12}:\frac{5}{6}\)

\(y=\frac{7}{12}.\frac{6}{5}\)

\(\Rightarrow y=\frac{7}{10}\)

a ) \(\left(y-\frac{2}{5}\right):\frac{4}{3}=\frac{3}{8}\)

   \(\left(y-\frac{2}{5}\right)=\frac{3}{8}\times\frac{4}{3}\)

     \(y-\frac{2}{5}=\frac{1}{2}\)

                 \(y=\frac{1}{2}+\frac{2}{5}\)

                \(y=\frac{5}{10}+\frac{4}{10}\)

                 \(y=\frac{9}{10}\)

 Vậy \(y=\frac{9}{10}\)

b ) \(y\times\frac{5}{6}=\frac{1}{4}+\frac{1}{3}\)

\(y\times\frac{5}{6}=\frac{3}{12}+\frac{4}{12}\)

\(y\times\frac{5}{6}=\frac{7}{12}\)

           \(y=\frac{7}{12}:\frac{5}{6}\)

          \(y=\frac{7}{12}\times\frac{6}{5}\)

        \(y=\frac{7}{10}\)

Vậy \(y=\frac{7}{10}\)

Chúc bạn học tốt !!!

[y+2/5] x 4/6 = 5/6

y + 2/5  =5/6 : 4/6

y + 2/5 = 5/4

y = 5/4 - 2/5

y = 17/20

thanhk bạn

I don't know

1)

( y - 1/5 ) : 2/3 = 3/4

y - 1/5            = 3/4 x 2/3

y - 1/5            = 1/2

y                   = 1/2 + 1/5

y                   = 7/10.

2)

7/4 - y x 5/6 = 1/2 + 1/3

7/4 - y x 5/6 = 5/6

7/4 - y         = 5/6 : 5/6

7/4 - y         = 1

y                = 7/4 - 1

y                = 3/4

C1 :(y-1/5):2/3=3/4

y-1/5=3/4.2/3

y-15=1/2

y=1/2+15

y=31/2

C2:

7/4-y.5/6=1/2+1/3

7/4-y.5/6=5/6

y.5/6=7/4-5/6

y.5/6=11/12

y=11/12:5/6

y=11/10

Cho mk sửa lại

C1 :(y-1/5):2/3=3/4

y-1/5=3/4.2/3

y-15=1/2

y=1/5+15

y=7/10

C2:

7/4-y.5/6=1/2+1/3

7/4-y.5/6=5/6

y.5/6=7/4-5/6

y.5/6=11/12

y=11/12:5/6

y=11/10

y = 0,125

\(1,25\times y=2,4+7,6\)

\(1,25\times y=10\)

                \(y=10:1,25\)

                \(y=8\)

\(\text{1,25 x y = 2,4 + 7,6}\)

\(\Rightarrow\text{1,25 x y = }\text{10}\)

\(\Rightarrow\text{ y = 10}:1,25=\text{8}\)

\(\text{Vậy y = 8}\)

1,25 x y = 2,4 + 7,6. Vậy 1,25 x y =10

           y = 10 : 1,25

           y = 8

=>2,5y=5,55

hay y=2,22

Đáp án B

Vì \(\left(x-y\right)^2\ge0;\left(2x+3y-10\right)^2\ge0\)

\(\Rightarrow\left(x-y\right)^2+\left(2x+3y-10\right)^2\ge0\)

\(\Rightarrow A=\left(x-y\right)^2+\left(2x+3y-10\right)^2-2\ge-2\) có gtnn là - 2

Dấu "=" xảy ra <=> \(\hept{\begin{cases}\left(x-y\right)^2=0\\\left(2x+3y-10\right)^2=0\end{cases}\Rightarrow\hept{\begin{cases}x-y=0\\2x+3y=10\end{cases}\Rightarrow}\hept{\begin{cases}x=2\\y=2\end{cases}}}\)

Vật GTNN của A là - 2 <=> x = y = 2

\(\hept{\begin{cases}x-y=0\\2x+3y-10=0\end{cases}\Rightarrow\hept{\begin{cases}x=y\\6y=10\end{cases}\Rightarrow}x=y=\frac{10}{6}=\frac{5}{3}}\)