Question

Tìm x, biết :

a) \(|2x-6|+5x=9\)

b) \(\frac{x+2}{327}+\frac{x+3}{326}+\frac{x+4}{325}+\frac{x+5}{324}+\frac{x+349}{5}=0\)

Answer 1

a) ta có:

 \(|2x-6|+5x=9\Leftrightarrow|2x-6|=9-5x\)

\(2x-6=9-5x\Leftrightarrow7x=15\Leftrightarrow x=\frac{15}{7}\)

\(2x-6=5x-9\Leftrightarrow3x=3\Leftrightarrow x=1\)

b) Ta có:

\(\frac{x+2}{327}+\frac{x+3}{326}+\frac{x+4}{325}+\frac{x+5}{324}+\frac{x+329}{5}+4=0\)

\(\Leftrightarrow\left(x+329\right)\left(\frac{1}{327}+\frac{1}{326}+\frac{1}{325}+\frac{1}{324}+\frac{1}{5}\right)=0\)

do \(\frac{1}{327}+\frac{1}{326}+\frac{1}{325}+\frac{1}{324}+\frac{1}{5}\ne0\)nên \(x+329=0\Leftrightarrow x=-329\)

Vậy ............................................. chúc bn hok tốt ^-^