Answer:
f(x)
first you have to multiply 3×48 =144 and divided by 12 and answer comes 12 and you have to add 12 +12 which is 24 which is written in the middle of 3x^2 and 48
3x^2 +x(12+12) +48
3x^2 + 12x +12x +48
3x(x +4) +12(x +4)
(x+4) (3x +12) answer
2. there is not zero while solving f
but think this is the answer
