Answer:
x + 4
Step-by-step explanation:
Use synthetic division with -3 as the divisor. This -3 comes from (x + 3).
-3 / 1 7 12
-3 -12
--------------------
1 4 0
Since the remainder is 0, -3 is a root and (x + 3) is a factor. The other factor has the coefficients 1 and 4, which works out to (x + 4).
x^2+7x +12 divided by x+3 is x + 4.
