Using formula method
We know that algebraic multiplication and factorial analysis are inverse transformations: A2-B2 = (a+b) (a-b) A2+2ab+B2 = (a+b) 2a2-2ab+B2 = (a-b) 2.
If the multiplication formula is reversed, it is a polynomial analysis factor. If the multiplication formula is reversed, it can be used to analyze some polynomials. The key point of this analysis factor is called formula method.
Square difference formula: a2-b2=(a+b)(a-b) This formula is square. Language: the square of two numbers is the difference formula between the sum of these two numbers and the difference between these two numbers (3) factorial analysis. In factorial analysis, if there is a common factor, first mention the common factor, and then further analyze the factorization until each polynomial factor can no longer be decomposed.
Reverse the multiplication formula (atb)2=a2+2ab+b2 and (a-b)2=a2-2ab+b2, and you can get: A2+2AB+B2 = (A+B) 2A2-2AB+B2 = (A-B) 2.
That is to say, the sum of squares of two numbers plus twice the product of "or minus" is equal to the square of the sum (or difference) of these two numbers, and the formulas a22ab+b2 and a2-2ab+b2 are called completely flat modes.
The factorial formula =(aman)+(bm+bn)-a(m+n)+b(m+n) is not called polynomial analysis of factorial common factor (m+n), so we can still inherit the analytical formula = (AM+AN)+(BM+BN) A (M+N)+. (a+b)
If the numerator or denominator of a fraction is marked to n power, it can be marked by fraction, so that the even power of the whole fraction is positive and the odd power is negative. Of course, the numerator and denominator of a simple fraction can be directly multiplied and then press-1.