答：利用换底公式log3(π-1)＝log9(x+5)log3(π-1)＝log3(x+5)/log3(9)log3(π-1)＝log3(x+5)/22log3(π-1)＝log3(x+5)log3(π-1)²＝log3(x+5)所以：x+5=(π-1)²所以：x=(π-1)²-5x=π²-2π-4...