3a+2b=0∴b=-3a/2原式=(a²-b²+2b²)/(a²-b²)÷(a-b+2b)/(a-b)=(a²+b²)/(a+b)(a-b) ×(a-b)/(a+b)=(a²+b²)/(a+b)²=(a²+9a²/4)/(a-3a/2)²=13