①(-5a-2b)( )=4b^2-25a^2 ②(a-___)^2=a^2-8ab+___
问题描述:
①(-5a-2b)( )=4b^2-25a^2 ②(a-___)^2=a^2-8ab+___
答
①(-5a-2b)(5a-2b )=4b^2-25a^2
②(a-4b)^2=a^2-8ab+16b^2