Answer:
-21.
Explanation:
x^2 + 4x - 21 = 0
To factor this we need 2 numbers whose sum id + 4 and whose produce is -21.
These are - 3 and + 7 , so the factors are:
(x - 3)(x + & = 0
x = 3, -7.
3.6m questions
4.5m answers