当两个同底的幂相乘时,指数相加。所以当你分两个有着相同基础的异能者,你减去指数相加。换句话说,对于所有实数 一个 , b 和 c ,在那里 一个 ≠ 0 ,
一个 b 一个 c = 一个 b−c
这里要做的是消去分子和分母的公因式。例子:
9 5 9 2 = 9 ⋅ 9 ⋅ 9 ⋅ 9 ⋅ 9 9 ⋅ 9 = 9 ⋅ 9 ⋅ 9 = 9 3.