4a(x+3y)²+12a(x+3y)+9a. 因式分解

4a(x+3y)²+12a(x+3y)+9a. 因式分解
4a(x+3y)²+12a(x+3y)+9a. 因式分解

4a(x+3y)²+12a(x+3y)+9a. 因式分解
=a·[4(x+3y)的平方+12(x+3y)+9]
=a·[2(x+3y)+3]的平方
=a·(2x+6y+3)的平方

4a(x+3y)²+12a(x+3y)+9a
=a[4(x+3y)²+12(x+3y)+9]=a[2(x+3y)+3]²
=a(2x+6y+3)²

4a(x+3y)^2+12a(x+3y)+9a
=a[4(x+3y)^2+12(x+3y)+9]
=a[2(x+3y)+9]^2
=a(2x+6y+9)^2。

用十字相乘，变为
(2a(X+3y)+3a)(2(x+3y)+3