\(\dfrac{242}{363}+\dfrac{1616}{2121}=\dfrac{2}{7}y\)

\(\dfrac{2\cdot121}{3\cdot121}+\dfrac{16\cdot101}{21\cdot101}=\dfrac{2}{7}y\)

\(\dfrac{2}{7}y=\dfrac{2}{3}+\dfrac{16}{21}\)

\(\dfrac{2}{7}y=\dfrac{10}{7}\)

\(y=\dfrac{10}{7}\div\dfrac{2}{7}=5\)

nhân y mà

242/363 + 1616/ 2121= 5/7 x y

\(\frac{2}{3}+\frac{16}{21}=\frac{5}{7}\)x y

\(\frac{14}{21}\)+\(\frac{16}{21}\)= \(\frac{5}{7}\)x y

\(\frac{10}{7}\)=\(\frac{5}{7}\)x y

\(\frac{10}{7}\): \(\frac{5}{7}\)=y

\(\frac{10}{7}\)x \(\frac{7}{5}\)=y

2=y

vậy y=2

\(\frac{242}{363}+\frac{1616}{2121}=\frac{5}{7}\times y\)

\(\frac{121\times2}{121\times3}+\frac{101\times16}{101\times21}=\frac{5}{7}\times y\)

\(\frac{2}{3}+\frac{16}{21}=\frac{5}{7}\times y\)

\(\frac{10}{7}=\frac{5}{7}\times y\)

\(\Rightarrow y=\frac{10}{7}:\frac{5}{7}\)

\(y=2\)

M=5 nhé bạn , rất dễ mà

\(\frac{242}{363}+\frac{1616}{2121}=\frac{2}{7}.\frac{2015}{A}\)

\(\frac{11.11.2}{11.11.3}+\frac{101.16}{101.21}=\frac{2}{7}.\frac{2015}{A}\)

\(\frac{2}{3}+\frac{16}{21}=\frac{2}{7}.\frac{2015}{A}\)

\(\Rightarrow\frac{2}{7}.\frac{2015}{A}=\frac{10}{7}\)

\(\frac{2015}{A}=\frac{10}{7}:\frac{2}{7}\)

\(\frac{2015}{A}=5\)

\(A=2015:5\)

\(A=403\)

\(\left(\frac{242}{363}+\frac{1616}{2121}\right)=\frac{2}{7}.\frac{2015}{A}\)

\(\Leftrightarrow\left(\frac{2}{3}+\frac{16}{21}\right)=\frac{2}{7}.\frac{2015}{A}\)

\(\Leftrightarrow\frac{10}{7}=\frac{2}{7}.\frac{2015}{A}\)

\(\Leftrightarrow5=\frac{2015}{A}\)

\(\Leftrightarrow A=403\)

` 242/363 + 1616/2121 = 2/7 xxy`

`2/7 xxy= 2/3 + 16/21`

`2/7 xxy= 14/21 +16/21`

`2/7 xxy= 30/21`

`y=10/7 : 2/7`

`y=10/7 xx 7/2`

`y=70/14`

`y=5`

__

` (y + 1/4) + (y + 1/16) + (y + 1/16) =2`

`(y+y+y)+(1/4 + 1/16+1/16)=2`

`3y + (4/16 +1/16 +1/16)=2`

`3y + 6/16=2`

`3y=2-6/16`

`3y= 32/16-6/16`

`3y= 26/16`

`y=26/16 : 3`

`y=26/48`

`y=13/24`

\(a,\dfrac{242}{363}+\dfrac{1616}{2121}=\dfrac{2}{7}\times y\)

\(\dfrac{2}{7}\times y=\dfrac{2\times121}{3\times121}+\dfrac{16\times101}{21\times101}\)

\(\dfrac{2}{7}\times y=\dfrac{2}{3}+\dfrac{16}{21}\)

\(\dfrac{2}{7}\times y=\dfrac{14}{21}+\dfrac{16}{21}\)

\(\dfrac{2}{7}\times y=\dfrac{30}{21}\)

\(\dfrac{2}{7}\times y=\dfrac{10}{7}\)

\(y=\dfrac{10}{7}:\dfrac{2}{7}\)

\(y=\dfrac{10}{7}\times\dfrac{7}{2}\)

\(y=5\)

\(---\)

\(b,\left(y+\dfrac{1}{4}\right)+\left(y+\dfrac{1}{16}\right)+\left(y+\dfrac{1}{16}\right)=2\)

\(\left(y+y+y\right)+\left(\dfrac{1}{4}+\dfrac{1}{16}+\dfrac{1}{16}\right)=2\)

\(3\times y+\left(\dfrac{4}{16}+\dfrac{2}{16}\right)=2\)

\(3\times y+\dfrac{6}{16}=2\)

\(3\times y+\dfrac{3}{8}=2\)

\(3\times y=2-\dfrac{3}{8}\)

\(3\times y=\dfrac{16}{8}-\dfrac{3}{8}\)

\(3\times y=\dfrac{13}{8}\)

\(y=\dfrac{13}{8}:3\)

\(y=\dfrac{13}{8}\times\dfrac{1}{3}\)

\(y=\dfrac{13}{24}\)

#\(Toru\)

\(\left(\dfrac{242}{363}+\dfrac{1616}{2121}\right)=\dfrac{2}{7}.x\)

\(\Leftrightarrow\dfrac{242}{363}\left(1+\dfrac{8}{7}\right)=\dfrac{2}{7}.x\)

\(\Leftrightarrow\dfrac{242}{363}.\dfrac{15}{7}=\dfrac{2}{7}.x\)

\(\Leftrightarrow\dfrac{10}{7}=\dfrac{2}{7}.x\)

\(\Leftrightarrow x=\dfrac{10}{7}:\dfrac{2}{7}\)

\(\Leftrightarrow x=\dfrac{10}{7}.\dfrac{7}{2}\)

\(\Leftrightarrow x=5\)

=>x*2/7=(2/3+16/21)=14/21+16/21=30/21=10/7

=>x=5