Question

Factor x4 + 13x2 + 36.

Answer 1

Hello!

x⁴ + 13x² + 36

= x⁴ + 9x² + 4x² + 36

= (x⁴ + 9x²) + (4x² + 36)

= x²(x² + 9) + 4(x² + 9)

= (x² + 4)(x² + 9)