Current location - Training Enrollment Network - Mathematics courses - The seventh grade mathematics basic training Volume I Hunan Education Edition
The seventh grade mathematics basic training Volume I Hunan Education Edition
1 means that the square of 3 is 9, and the second one is 9 just like the first one.

2, the two are equal, because the expansion of the two formulas is equal, I will learn it later!

3, of course, under any conditions.

4, that is, using the second formula, is the square of 1 = 1.