D the product of (x + 3)(x − 3).

x2 − 6x + 9
x2 + 6x + 9
x2 + 9
x2 − 9

Answer :

Step-by-step explanation :

We can use the formula that :

(a + b) (a - b) = a(a - b ) + b(a - b)

= a² - ab + ab - b² = a² - b²

_________________________

(x + 3) (x - 3)

We have :

a = x

b = 3

So :

( x + 3 ) ( x - 3 )

x (x - 3 ) + 3 (x - 3 )

x² - 3x + 3x - 9

x² - 9

Answer = x² - 9

step-by-step explanation:

no, her answer is not correct.   we square the lengths of all sides and then determine whether the pythagorean theorem holds here:

9² + 15² = 306.   this is not equal to the square of the longest side ( that square being 395.   answer c is correct.