问题
填空题
计算:y(2y-3)=______;(x+3)(x-4)=______.
答案
y(2y-3)
=y•2y+y•(-3)
=2y2-3y;
(x+3)(x-4)
=x2-4x+3x-12
=x2-x-12.
故答案为:2y2-3y,x2-x-12.
计算:y(2y-3)=______;(x+3)(x-4)=______.
y(2y-3)
=y•2y+y•(-3)
=2y2-3y;
(x+3)(x-4)
=x2-4x+3x-12
=x2-x-12.
故答案为:2y2-3y,x2-x-12.