Answer:
(3f - 2)²
Explanation:
Given
9f² - 12f + 4
Consider the factors of the product of the coefficient of the f² term and the constant term which sum to give the coefficient of the f- term.
product = 9 × 4 = 36 and sum = - 12
The factors are - 6 and - 6
Use these factors to split the f- term
9f² - 6t - 6t + 4 ( factor the first/second and third/fourth terms )
= 3f(3f - 2) - 2(3f - 2) ← factor out (3f - 2) from each term
= (3f - 2)(3f - 2)
= (3f - 2)²