完全平方公式有如下两个:1.(a+b)~2=a~2+2ab+b~22.(a-b)~2=a~2-2ab+b~2熟练地掌握了它们的正向应用后,你是否想到过逆向应用它们?事实上,逆向应用它们,能把形如a~2±2ab+b~2的式子化为形如(a±b)~2的式子.这种和差化积的思想方法,在解题中值得我们一试! The perfect square formula has the following two: 1. (a + b) ~ 2 = a ~ 2 + 2ab + b ~ 22. (ab) ~ 2 = a ~ 2-2ab + b ~ 2 Skilledly mastered their positive Have you ever thought about applying them in the reverse direction when applied? In fact, applying them in reverse applies to the form of a ± 2 ± 2 ab + b ~ 2 as an expression of (a ± b) ~ 2. This method of thinking and the product of the difference in the problem-solving is worth a try!