题目在横线上填入适当的整式:(1)(−3x2+2y2)((1)(-3x^{2}+2y^{2})((1)(−3x2+2y2)(______)=9x4−4y4)=9x^{4}-4y^{4})=9x4−4y4；(2)a2+3ab+b2+______=(a−b)2(2)a^{2}+3ab+b^{2}+\_\_\_\_\_\_=\left(a-b\right)^{2}(2)a2+3ab+b2+______=(a−b)2.知识点：因式分解章节：未标注
