x^- 3x + 9/4 = (x-3/2)^2(2)a^4 + 10a^2 + 25 = (a^2 + 5)^2(3)9a^2b^2 + 15ab +25/4 = (3ab +5/2^2(4)x^4 + x^2 + 1/4 = ( x^2 + 1/2)^2
看不懂啊,亲,这是小学题目吗??