28.12 9.2812 28.28fx=x12 x根9
问题描述：
28.12 9.2812 28.28fx=x12 x根9
答
x∈9正无穷t=x^28-28x 12-51ab≥-28a^28-28b^28
28.12 9.2812 28.28fx=x12 x根9
x∈9正无穷t=x^28-28x 12-51ab≥-28a^28-28b^28