\(\left(\frac{1}{24.25}+\frac{1}{25.26}+...+\frac{1}{29.30}\right).120+y:\frac{1}{3}=-4\)
\(\Leftrightarrow\)\(\left(\frac{1}{24}-\frac{1}{25}+\frac{1}{25}-\frac{1}{26}+...+\frac{1}{29}-\frac{1}{30}\right).120+y:\frac{1}{3}=-4\)
\(\Leftrightarrow\)\(\left(\frac{1}{24}-\frac{1}{30}\right).120+y:\frac{1}{3}=-4\)
\(\Leftrightarrow\)\(1+3y=-4\)
\(\Leftrightarrow\)\(3y=-5\)
\(\Leftrightarrow\)\(y=-\frac{5}{3}\)
Vậy...
Ta có :
\(\left(\frac{1}{24.25}+\frac{1}{25.26}+...+\frac{1}{29.30}\right).120+y:\frac{1}{3}=-4\)
\(\Rightarrow\left(\frac{1}{24}-\frac{1}{25}+\frac{1}{25}-\frac{1}{26}+...+\frac{1}{29}-\frac{1}{30}\right).120+y.3=-4\)
\(\Rightarrow\left(\frac{1}{24}-\frac{1}{30}\right).120+y.3=-4\)
\(\Rightarrow\left(\frac{5}{120}-\frac{4}{120}\right).120+y.3=-4\)
\(\Rightarrow\frac{1}{120}.120+y.3=-4\)
\(\Rightarrow1+y.3=-4\)
\(\Rightarrow3y=-4-1\)
\(\Rightarrow3y=-5\)
\(\Rightarrow y=-\frac{5}{3}\)
Vậy \(y=-\frac{5}{3}\)
\(\left(\frac{1}{24.25}+\frac{1}{25.26}+...+\frac{1}{29.30}\right).120+y:\frac{1}{3}=-4.\)
\(\Leftrightarrow\left(\frac{1}{24}-\frac{1}{25}+\frac{1}{25}-\frac{1}{26}+...+\frac{1}{29}-\frac{1}{30}\right).120+y:\frac{1}{3}=-4\)
\(\Leftrightarrow\left(\frac{1}{24}-\frac{1}{30}\right).120+y.\frac{3}{1}=-4\)
\(\Leftrightarrow\frac{1}{120}.120+3y=-4\)
\(\Leftrightarrow1+3y=-4\Leftrightarrow3y=-5\)
\(\Leftrightarrow y=\frac{-5}{3}\)
\(\left(\frac{1}{24.25}+\frac{1}{25.26}+...+\frac{1}{29.30}\right).120+\frac{y}{3}=-4\)
\(\Rightarrow\left(\frac{1}{24}-\frac{1}{30}\right).120+\frac{y}{3}=-4\)
\(\Rightarrow\frac{1}{120}.120+\frac{y}{3}=-4\)
\(\Rightarrow1+\frac{y}{3}=-4\)
\(\Rightarrow\frac{y}{3}=-5\)
\(\Rightarrow y=-15\)
\(\left(\frac{1}{24.25}+\frac{1}{25.26}+....+\frac{1}{29.30}\right)\) \(.120+y:\frac{1}{3}=-4\)
<=> \(\left(\frac{1}{24}-\frac{1}{25}+\frac{1}{25}-\frac{1}{26}+...+\frac{1}{29}-\frac{1}{30}\right)\)\(.120+3y=-4\)
<=> \(\left(\frac{1}{24}-\frac{1}{30}\right).120+3y=-4\)
<=> \(\frac{1}{120}.120+3y=-4\)
<=> \(1+3y=-4\)
<=> \(3y=-5\)
<=> \(y=\frac{-5}{3}\)
