Question

Factor
r^4-25

Answer 1

\[a^2-b^2=(a+b)(a-b)\]

Answer 2

r^4-25 = (r^2)^2 - 5^2
= (r^2-5)(r^2+5)
= (r-√5)(r+√5)(r^2 +5)

Answer 3

\[a^2=(r^2)^2=r^4\]
\[b^2=5^2\]

Answer 4

\[(-5+r^2) (5+r^2) \]