Answer:
The last step is incorrect.
Step-by-step explanation:
5(x² + 9) should be the last step.
The answerer mistakened (x² + 9) for a "difference of squares". You can se the difference of squares factoring when you have a square number being subtracted from another square number. The general rule looks like:
[tex]a^{2} - b^{2} = (a+b)(a-b)[/tex]
"Difference" means the answer when subtracting, but there is a plus sign "+" which means adding.
You can't factor "x² + 9" any further.
