Answer:
(x - 2)(3x^2 + 5)
Explanation:
All four terms here have 3 as a factor. Factor out 3:
3x^(3)-6x^(2)+15x-30 => 3(x^3 - 2x^2 + 5x - 10)
The last two terms can be rewritten as 5(x - 2). The first two terms can be rewritten as 3x^2(x - 2). So (x - 2) is a factor of 3(x^3 - 2x^2 + 5x - 10). We get:
3x^2(x - 2) + 5(x - 2) = (x - 2)(3x^2 + 5)