Answer:
d^2 - 14d + 49 = (d-7)(d-7).
Explanation:
Given the expression is d^2 - 14d + 49.
d^2 - 14d + 49 = d^2 - 2*7*d + 7^2
We know the formula of square of difference as given below:-
x^2 - 2*x*y + y^2 = (x-y)^2
Using the above formula in the problem, here x = d and y = 7.
d^2 - 2*7*d + 7^2 = (d-7)^2
d^2 - 2*7*d + 7^2 = (d-7)(d-7)
So, d^2 - 14d + 49 = (d-7)(d-7).