幫幫手!!!

1.4(x+y)²+12(x+y)+9---------- ------------ans:(2x- 2y+3)²
=[2(x+y)]² + 12(x+y) + 9
=[2(x+y) + 3]²
=(2x+2y+3)²

2. (x-3)²-4x²-------------------- --ans:-3(x-1)(x+3)
=(x-3)² - (2x)²
=[(x-3) + 2x][(x-3) - 2x]
=(3x-3)(-3-x)
=3(x-1)(-3-x)
= -3(x-1)(x+3)