Current location - Training Enrollment Network - Mathematics courses - A small junior high school math problem
A small junior high school math problem
Method 1: Solution: (A 2) * (B-C)+(B 2) (C-A)+(C 2) (A-B)

=a^2b-a^2c+b^2c-b^2a+c^2a-c^2b

=ab(a-b)+bc(b-c)+ac(c-a)

=b(a^2-ab+cb-c^2)+ac(c-a)

=b[(a+c)(a-c)-b(a-c)]+ac(c-a)

=b(a-c)(a+b-c)-ac(a-c)

=(a-c)(ab+b^2-bc-ac)

=(a-c)(a-b)(b-c)=0

So a-c=0 or a-b=0 or b-c=0.

That is, at least two of the three numbers A, B and C are equal.

Method 2:

To expand the formula, you must

Answer? b-a? c+b? c-b? a+c? b-c? a=0

(a-b)(c? -ab-ac+ab)=0

(a-b)(b-c)(c-a)=0

So: at least two of the three numbers A, B and C are equal.

I wish you progress in your study every day. Come on! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !