Answer:
3 x^4 + -75
Explanation:
Expand the following:
3 (x^2 + 5) (x^2 - 5)
(x^2 + 5) (x^2 - 5) = (x^2) (x^2) + (x^2) (-5) + (5) (x^2) + (5) (-5) = x^4 - 5 x^2 + 5 x^2 - 25 = x^4 - 25:
3 x^4 - 25
3 (x^4 - 25) = 3 x^4 + 3 (-25):
3 x^4 - 25×3
3 (-25) = -75:
Answer: 3 x^4 + -75