The answer is (f . g)(x) = - (34k + 17k⁷ + 17k⁵ + 40k³ + 20k² + 60).
Remember that :
(f . g)(x) = f(x) × g(x)
Hence :
- (f . g)(x) = (2k³ + k² + 3)(-17k⁵ - 20)
- (f . g)(x) = -34k⁸ - 17k⁷ - 17k⁵ - 40k³ - 20k² - 60
- (f . g)(x) = - (34k + 17k⁷ + 17k⁵ + 40k³ + 20k² + 60)