a: Khi a=3 thì (1) sẽ là
\(\dfrac{3-2x}{1}+\dfrac{3-2x}{5}=\dfrac{30}{5}=6\)
=>3-2x+3/5-2/5x=6
=>-12/5x+18/5=6
=>-12/5x=12/5
=>x=-1
b: \(\Leftrightarrow\left(a+2x\right)\left(a+2\right)-\left(a-2x\right)\left(a-2\right)=6a\)
=>\(a^2+2a+2ax+4x-a^2+2a+2xa-4x=6a\)
=>4a+4xa=6a
=>4xa-2a=0
=>2a(2x-1)=0
=>x=1/2
\(\dfrac{a+2x}{a-2}-\dfrac{a-2x}{a+2}=\dfrac{6a}{a^2-4}\)
a) Khi a = 3 ta có :
\(3+2x-\dfrac{3-2x}{5}=\dfrac{18}{5}\\ \Leftrightarrow3+2x=\dfrac{18}{5}+\dfrac{3-2x}{5}\\ \Leftrightarrow3+2x=\dfrac{21-2x}{5}\\ \Leftrightarrow15+10x=21-2x\\ \Leftrightarrow12x=6\\ \Leftrightarrow x=\dfrac{1}{2}\)
