题目因式分解（直接写出答案）(1)9b2−(a+1)2=______.(1)9b^{2}-\left(a+1\right)^{2}= \_\_\_\_\_\_.(1)9b2−(a+1)2=______.(2)16x2+1−8x=______.(2)16x^{2}+1-8x= \_\_\_\_\_\_.(2)16x2+1−8x=______.(3)x3−5x2−6x=______.(3)x^{3}-5x^{2}-6x= \_\_\_\_\_\_.(3)x3−5x2−6x=______.(4)x2−y2−1+2y=______.(4)x^{2}-y^{2}-1+2y= \_\_\_\_\_\_.(4)x2−y2−1+2y=______.知识点：运用公式法章节：未标注
