Question

[Huynh Thi Kim Anh]

(1/25x26 +1/26x27+.......+1/29x30)x150+1,03:[1,03x(y-1)]=22

Answer 1

[︵✰ßล∂ ß๏у®]

\(\left(\frac{1}{25.26}+\frac{1}{26.27}+...+\frac{1}{29.30}\right)\cdot150+1,03\div\left[1,03\cdot\left(y-1\right)\right]\text{ }=22\)

\(\Rightarrow\left(\frac{1}{25}-\frac{1}{26}+\frac{1}{26}-\frac{1}{27}+...+\frac{1}{29}-\frac{1}{30}\right)\cdot150+1,03\div\left[1,03\cdot\left(y-1\right)\right]=22\)

\(\Rightarrow\left(\frac{1}{25}-\frac{1}{30}\right)\cdot150+1,03\div\left[1,03\cdot\left(y-1\right)\right]=22\)

\(\Rightarrow\frac{1}{150}\cdot150+1,03\div\left[1,03\left(y-1\right)\right]=22\)

\(\Rightarrow1+1,03\div\left[1,03\left(y-1\right)\right]=22\)

\(\Rightarrow1,03\left(y-1\right)=1,03\div\left(22-1\right)\)

\(\Rightarrow1,03y-1,03=1,03\div21\)

\(\Rightarrow1,03y=\frac{103}{2100}+1,03\)

\(\Rightarrow1,03y=\frac{1133}{1050}\)

\(\Rightarrow y=\frac{1133}{1050}\div\frac{103}{100}=\frac{1133}{1050}\cdot\frac{100}{103}=\frac{22}{21}\)

Vậy y = \(\frac{22}{21}\)

Dấu " . " là dấu nhân nhé 

Answer 2

[nguyễn tuấn thảo]

\(\left(\frac{1}{25\times26}+\cdot\cdot\cdot+\frac{1}{29\times30}\right)\times150+1\frac{3}{100}:[1\frac{3}{100}\times(y-1)]=22\)

\(\Rightarrow\left(\frac{1}{25}-\frac{1}{26}+\cdot\cdot\cdot+\frac{1}{29}-\frac{1}{30}\right)\times150:\left(y+1\right)=22\)

\(\Rightarrow\left(\frac{1}{25}-\frac{1}{30}\right)\times150:\left(y+1\right)=22\)

\(\Rightarrow\frac{1}{150}\times150:\left(y+1\right)=22\)

\(\Rightarrow1:\left(y+1\right)=22\)

\(\Rightarrow y+1=\frac{1}{22}\)

\(\Rightarrow y=\frac{1}{22}-1=\frac{-21}{22}\)