Explanation:
The factors of 9x² +49y² are:
D. (3x + 7y)(3x + 7y) and C. (3x - 7y)(3x - 7y)
We can use the identity:
a² + b² = (a + b)(a - b)
To factor the expression 9x² + 49y², let a = 3x and b = 7y. Then we have:
9x² + 49y² = (3x)² + (7y)² = (3x + 7y)(3x - 7y)
So the factors of 9x² + 49y² are (3x + 7y) and (3x - 7y). We can see that these factors are not prime, as they can be factored further into (3x + 7y)(3x + 7y) and (3x - 7y)(3x - 7y).