Final answer:
The perfect square of a binomial is an expression that can be written as (a + b)² or (a - b)². Out of the given options, B. 25x² - 100 and D. x² + 2xy² + y⁴ can be expressed as perfect squares of binomials.
Step-by-step explanation:
The perfect square of a binomial is an expression of the form (a + b)² or (a - b)², where a and b are real numbers. To determine which of the given options is a perfect square of a binomial, we need to identify if the expression can be written in the form (a + b)² or (a - b)². Let's go through each option:
- A. x² + y²: This is not a perfect square of a binomial because it cannot be written in the form (a + b)² or (a - b)².
- B. 25x² - 100: This is a perfect square of a binomial. It can be written as (5x)² - 10².
- C. x² - 3xy + 9y²: This is not a perfect square of a binomial because it cannot be written in the form (a + b)² or (a - b)².
- D. x² + 2xy² + y⁴: This is a perfect square of a binomial. It can be written as (x + y²)².
Therefore, the correct answer is B. 25x² - 100 and D. x² + 2xy² + y⁴ as they can be expressed as perfect squares of binomials.