Answer: -7twice
Step-by-step explanation:
This is a question on root of quadratic equation. The interpretation of the question 
x² 14x + 49 is 
x² + 14x + 49 = 0.meaning that we are to find two possible values for x that will make the expression equal 0.
We can use any of the methods earlier taught. For the purpose of this class, I am using factorization methods
 x² + 14x + 49 = 0
Now, find the product of the first and the last terms, is
x² × 49 = 49ײ
Now find two terms such that their productbis 49x² and their sum equals 14x, the one in the middle.
We have several factors of 49x² but only one will give sum of 14x. Because of the time, I will only go straight to the required factors .
 49x² = 7x × 7x and the sum gives 14x the middle terms..
Now we now replace the middle one by the factors and then factorize by grouping.
x² + 14x + 49 = 0
x² + 7x + 7x + 49 = 0
x(x + 7) + 7(x + 7) = 0
 (x + 7)(x + 7). = 0
 Now to find this value of x, 
 x + 7 = 0
 x. = -7twice.
 The root of the equation = -7twice.