若a／b=2,求分式a²+ab-b²／a²-2ab+2b²的值
网友回答
a／b=2a=2ba²+ab-b²／a²-2ab+2b²
=(4b²+2b²-b²)/(4b²-4b²+2b²)
=5/2======以下答案可供参考======
供参考答案1:
a／b=2a=2ba²+ab-b²／a²-2ab+2b²
=((2b)²+(2b)*b-b²)/((2b)²-2*(2b)*b+2b²)
=(4+2-1)/(4-4+2)
=5/2=2.5供参考答案2:
不知道供参考答案3:
a／b=2a=2ba²+ab-b²／a²-2ab+2b²
=4b²+2b²-b²/4b²-4b²+2b²
=5b²/2b²
=5/2