A 2. 32r+1-4.3"-15=0的解為 37x3'-9x37-15:0 → 3* × 3 - 4 × 3* -15 = 0 -3' × 3* -| x3x 令39 二七 3 t - t-15 = 0 03 =(4-7) (5+77) 3. 28 x-x-x=15 x(x²-x-1)=15 (3-3) 3 -3x-15=0 30x32x-3x-15=0 若9+3=4x3*,則x=_ 5 += -1/3 m3 (145) t 3-3 * | -x