Question

which number is to be added to x²-14×x to get a perfect square​

Answer 1

Answer:

The third term must be a perfect square as well.  

 

The general form of the factored trinomial will be:

 

(x + a)(x + b) [since the coefficient of x2 is 1, which is also a perfect square]

 

Now, what two numbers added together equal 14 that would provide a perfect square for the third term?

 

How about 7 and 7; 7 + 7 = 14 and 7 * 7 = 49

 

So, the factors are:

 

(x + 7)(x + 7) = x2 + 14x + 49 (the number we need to add)

 

Hope this helps!