问题
填空题
计算:(x-2)(x+3)=______;(-2x-3)(-2x+3)=______.
答案
(x-2)(x+3)
=x2+3x-2x-6
=x2+x-6;
(-2x-3)(-2x+3)
=(2x+3)(2x-3)
=4x2-9.
故答案为:x2+x-6;4x2-9.
计算:(x-2)(x+3)=______;(-2x-3)(-2x+3)=______.
(x-2)(x+3)
=x2+3x-2x-6
=x2+x-6;
(-2x-3)(-2x+3)
=(2x+3)(2x-3)
=4x2-9.
故答案为:x2+x-6;4x2-9.