计算①2x／5x-3÷3／25x²-9·x／5x+3②a-1／a÷a-1／a²

计算①2x／5x-3÷3／25x²-9·x／5x+3②a-1／a÷a-1／a²
计算①2x／5x-3÷3／25x²-9·x／5x+3②a-1／a÷a-1／a²

计算①2x／5x-3÷3／25x²-9·x／5x+3②a-1／a÷a-1／a²
①2x／5x-3÷3／25x²-9·x／5x+3
=2x/(5x-3)÷3/(5x-3)(5x+3)*x(5x+3)
=2x²/3
②a-1／a÷a-1／a²
=(a-1)/a÷(a-1)/a²
=a