Question

中二数题=====(x-1)^2-144

Answer 1

(x-1)²-144 =x²-2x+1-144 =x²-2x-143 2007-01-25 00:56:15 补充： 方法1-------用十字相乘法计算 (x-1)²-144=x²-2x 1-144=x²-2x-143当你做到x²-2x-143你可以用十字相乘法:=(x-13)(x 11)－－－－－－－－－－－－－－－－－－－－－－－－－方法2------用平方差计算 (x-1)²-144=(x-1)²-12²=(x-1-12)(x-1 12)=(x-13)(x 11)2种方法都计到
(x-1)^2-144 =(x-1)^2-12^2 =[(x-1)-12][(x-1)+12] =(x-13)(x-11)
(x-1)^2-144 =(x-1)^2-12^2 =[(x-1)-12][(x-1)+12] =(x-13)(x-11) 2007-01-28 00:38:09 补充： 十字相乘法 is ok but it is not covered in form 2. Moreover
it is not a good method for this question since we saw a^2-b^2 patten in this question.