12x^2 + 21x + 9 = 0
3(4x^2+7x+3)=0
3(x )(4x ) ( +1)( +3)=0
3 (x+1) (4 x+3) = 0
Solve:
3 (x+1)=0
3 (x) (3)(+1)=0
3x+3=0
3x+3-3=0-3
3x=-3
3x/3=-3/3
x=-1
Solve
3(4 x+3) = 0
3(4 x) (3)(+3) = 0
12x+9=0
12x+9-9=0-9
12x=-9
12x/12=-9/12
x=-9/12=-3/4