a-b=2.(a+b)
=>a-b=2a+2b
=>a-2=b+2b
=>-1.a=3b
=>-1/3.a=b
Lại có: a-b=a:b
=>a-(-1/3).a=a:b
=>a+1/3.a=a.1/b
=>a.4/3=a.1/b
=>4/3=1/b
=>4b=3
=>b=3/4
=>a=3/4: (-1/3)=-9/4
Vậy a=-9/4,b=3/4
Ta có :
a-b=2(a+b)
=> a-b=2a+2b
=> a=2a+3b
=> a-2a=3b
=> -a=3b
=> b=\(\frac{-1}{3}a\)
Lại có :
2(a+b)=a:b
=> 2a+2b=a:b
=> 2a+ 2. \(\frac{-1}{3}a\)=a:\(\frac{-1}{3}a\)
=> 2a+\(\frac{-2}{3}a\)=a2.(-3)
=> a.\(\frac{4}{3}\)=a2.(-3)
=> 4/3=a.(-3)
=> a= -9/4
=> b= -1/3 . -9/4 = 3/4