平方差公式(a+b)(a-b)=a2-b2的结构特征是:左边是两个二项式相乘,这两个二项式中,有一项是完全相同,另一项互为相反数。右边是相同的项的平方与互为相反数的项的平方的差。公式中的a、b可以是数,也可以是代数式。因此,对一些繁杂的数字计算题,活用平方差公式,可使 The structural difference of the square difference formula (a+b)(ab)=a2-b2 is: The left side is the multiplication of two binomials. One of the two binomials is exactly the same, and the other is opposite. number. The right side is the difference between the square of the same term and the square of the opposite term. The a and b in the formula can be numbers or algebraic expressions. Therefore, for some complicated digital calculation problems, the square difference formula can be used to make