How do I factorise this?

Question

So I came across this question, and it stumped me. I'm not quite sure how to factorise this quadratic equation: 25p^2 − 40p + 16 − 9t^2. Please help!

Answer 1

We deal with two terms at a time. What's common among the first two? 5p

25p² - 40p = 5p(5p - 8)

16 - 9t² is the difference of two squares!

16 - 9t² = (4 - 3t)(4 + 3t)

25p² - 40p + 16 - 9t² = 5p(5p + 8) + (4 - 3t)(4 + 3t)