The main method is diagonal multiplication.
For example, the method of x 2+3x+2 = 0 is
Splitting the coefficients before x ^2 and 2 (i.e. 1 and 2).
1*1=11* 2 = 2, so
1 2
1 1
The result of diagonal multiplication adds up to 1*2+ 1* 1=3.
The number obtained is equal to the coefficient before x, so it holds.
It can be reduced to (x+2)(x+ 1)=0.
If not, here is a detailed explanation, which is more troublesome.
Methods First, the quadratic term is decomposed into (1 X quadratic term coefficient) and the constant term is decomposed into (1 X constant term), and then the third time a=2 b= 1 c= quadratic term coefficient ÷a d= constant term ÷b The fourth time a = 2b = 2. A=3 b=3 c= quadratic term coefficient ÷a d= constant term ÷b ... and so on until (ad+cb= linear term coefficient). The format of the final result is (ax+b)(cx+d).
I hope I can help you.
If you can't, you can keep asking me.
Hope to adopt