\(\frac{x+14}{86}+\frac{x+15}{85}+\frac{x+16}{84}+\frac{x+17}{83}+\frac{x+116}{4}=0\)
\(\Leftrightarrow\frac{x+14}{86}+\frac{x+15}{85}+\frac{x+16}{84}+\frac{x+17}{83}+\frac{x+100}{4}+4=0\)
\(\Leftrightarrow\left(\frac{x+14}{86}+1\right)+\left(\frac{x+15}{85}+1\right)+\left(\frac{x+14}{86}+1\right)+\left(\frac{x+13}{87}+1\right)+\frac{x+100}{4}=0\)
\(\Leftrightarrow\frac{x+100}{86}+\frac{x+100}{85}+\frac{x+100}{84}+\frac{x+100}{83}+\frac{x+100}{4}=0\)
\(\Leftrightarrow\left(x+100\right)\left(\frac{1}{86}+\frac{1}{85}+\frac{1}{84}+\frac{1}{83}+\frac{1}{4}\right)=0\)
\(\Leftrightarrow x+100=0\left(vì\frac{1}{86}+\frac{1}{85}+\frac{1}{84}+\frac{1}{83}+\frac{1}{4}\ne0\right)\)
\(\Leftrightarrow x=-100\)
vậy.............................
\(\left[\frac{\left(x+14\right)}{86}+1\right]+\left[\frac{\left(x+15\right)}{85}+1\right]+\left[\frac{\left(x+16\right)}{84}+1\right]+\left[\frac{\left(x+17\right)}{83}+1\right]\)\(+\left[\frac{\left(x+116\right)}{4}-4\right]=0\)
\(\frac{\Rightarrow\left(x+100\right)}{86}+\frac{\left(x+100\right)}{85}+\frac{\left(x+100\right)}{84}+\frac{\left(x+100\right)}{83}+\frac{\left(x+100\right)}{16}=0\)
\(\Rightarrow\left(x+100\right)\left(\frac{1}{86}+\frac{1}{85}+\frac{1}{84}+\frac{1}{83}+\frac{1}{16}\right)=0\)
\(\Leftrightarrow x+100=0\Rightarrow x=-100\)
Mặt khác :\(\frac{1}{86}+\frac{1}{85}+\frac{1}{84}+\frac{1}{83}+\frac{1}{16}\ne0\)
Vậy x=-100
_Chúc bn hc tốt
cảm ơn mọi người nhiều ạ
\(\frac{x+14}{86}+\frac{x+15}{85}+\frac{x+16}{84}+\frac{x+17}{83}+\frac{x+116}{4}=0\)\(=0\)
\(\Leftrightarrow\frac{x+14}{86}+1+\frac{x+15}{85}\)\(+1+\frac{x+16}{84}+1+\)\(\frac{x+17}{83}+1+\frac{x+116}{4}-4=0\)
\(\Leftrightarrow\frac{x+100}{86}+\frac{x+100}{85}\)\(+\frac{x+100}{84}+\frac{x+100}{83}\)\(+\frac{x+100}{4}=0\)
\(\Leftrightarrow\left(x+100\right).\)\(\left(\frac{1}{86}+\frac{1}{85}+\frac{1}{84}+\frac{1}{83}+\frac{1}{4}\right)\)
\(\Leftrightarrow x+100=0.Do\)\(\frac{1}{86}+\frac{1}{85}+\frac{1}{84}+\frac{1}{83}+\frac{1}{4}\) \(\ne0\)
\(\Rightarrow x=-100\)
https://diendan.hocmai.vn/threads/toan-8-giup-voi.195314/
hãy vô đây nha !!
\(\frac{x+14}{86}+\frac{x+15}{85}+\frac{x+16}{84}+\frac{x+17}{83}+\frac{x+116}{4}=0\)
\(\Leftrightarrow\frac{x+14}{86}+1+\frac{x+15}{85}+1+\frac{x+16}{84}+1+\frac{x+17}{83}+\frac{x+116}{4}-4=0\)
\(\Leftrightarrow\frac{x+100}{86}+\frac{x+100}{85}+\frac{x+100}{84}+\frac{x+100}{83}+\frac{x+100}{4}=0\)
\(\Leftrightarrow\left(x+100\right)\left(\frac{1}{86}+\frac{1}{85}+\frac{1}{84}+\frac{1}{83}+\frac{1}{4}\right)=0\)
\(\Leftrightarrow x+100=0.\)do\(\frac{1}{86}+\frac{1}{85}+\frac{1}{84}+\frac{1}{83}+\frac{1}{4}\ne0\)
\(\Rightarrow x=-100\)
\(\frac{x+14}{86}+\frac{x+15}{85}+\frac{x+16}{84}+\frac{x+17}{83}+\frac{x+116}{4}=0\)
\(\Rightarrow\frac{x+14}{86}+1+\frac{x+15}{85}+1+\frac{x+16}{84}+1+\frac{x+17}{83}+1\)
\(+\frac{x+116}{4}-4=0\)
\(\Rightarrow\frac{x+100}{86}+\frac{x+100}{85}+\frac{x+100}{84}+\frac{x+100}{83}+\frac{x+100}{4}=0\)
\(\Rightarrow x=-100\)