Ta có:
A+B=(A-B)X11
A+B=AX11-BX11
=> A+BX12=AX11
=> BX12=AX10
A/B=12/10=6/5
Ta có: a + b = 11 x (a - b)
=> a + b = 11 x a - 11 x b
=> 11 x a - a - 11 x b - b = 0
=> 10 x a - 12 x b = 0
=> 2 x ( 5 x a - 6 x b ) = 0
=> 5 x a - 6 x b = 0
=> 5 x a = 6 x b
=> \(\frac{a}{b}=\frac{6}{5}\)