Answer:
see explanation
Step-by-step explanation:
note when x = - 3
(- 3)³ + 2(- 3)² + 4(- 3) + 21 = - 27 + 18 - 12 + 21 = 0
hence x = - 3 is a zero and (x + 3) is a factor and dividing gives
= (x + 3)(x² - x + 7)
For zeros equate to zero
(x + 3)(x² - x + 7) = 0
equate each factor to zero and solve for x
x + 3 = 0 ⇒ x = - 3
x² - x + 7 = 0 ← solve using quadratic formula
x = (1 ±
) / 2 = (1 ± 3i
) / 2
x =
± 
zeros are x = - 3, x =
±
Option D. 2(n + 9) is the right answer
Step-by-step explanation:
The word problems are converted into mathematical problems to solve simply.
for the given problem
"two times the sum of a number and 9"
Let n be a number then
when there is and between two things they are performed first then next operation is performed so
the sum of a number and 9

Then
two times the sum of a number and 9

Hence,
Option D. 2(n + 9) is the right answer
Keywords: Mathematical notation
Learn more about mathematical notation at:
#LearnwithBrainly
That would be 6 just put the the whole number over one and keep flip change
Je ne parle le Français très bonne, mais je te vais aider. Le total est 40kg et la valise pèse 20kg donc 40-20=20. La réponse est 20kg.