Answer:
3
(-5x - 3)(-5x + 3)
Explanation:
Difference of squares is a special type of factoring when you are subtracting two numbers that are perfect squares. Perfect squares are numbers that, when you find its square root, it is a whole number.
Difference of squares follows this rule:
a² - b² = (√a² - √b²)(√a² + √b²) = (a - b)(a + b)
Notice in the factored form, you take the same number in both brackets. In one set of brackets you add the numbers. In the other brackets, you subtract the numbers.
In (-5x - 3)(-5x + __), the blank in the second bracket will use the same number as the second number in the first brackets.
(-5x - 3)(-5x + 3)