Answer:
(d - 2)²
Step-by-step explanation:
d² - 4d + 4 ← is a perfect square of the form
(x ± a )² = x² ± 2ax + a²
compare coefficients of like terms
- 2a = - 4 ⇒ a = 2 and a² = 4, hence
d² - 4d + 4 = (d - 2)²
Rewrite it in the form a^2 - 2ab + b^2, where a = d and b = 2
d^2 - 2(d)(2) + 2^2
Use the Square of Difference: (a - b)^2 = a^2 - 2ab + b^2
(d - 2)^2
Look AT IMAGE
D
Step-by-step explanation: always remember that sign as irrational
