Answer: x = {-3, -1, 1, 7}
<u>Step-by-step explanation:</u>
f(x) = x⁴ - 4x³ - 22x² + 4x + 21
possible roots are: +/- 1, 3, 7, 21
Let's try x = 1
1 | 1 -4 -22 4 21
<u>| ↓ 1 -3 -25 -21 </u>
1 -3 -25 -21 0 <em>remainder is 0 so (x - 1) is a factor</em>
(x - 1)(x³ - 3x² - 25x - 21)
Next, let's try x = -1
-1 | 1 -3 -25 -21
<u>| ↓ -1 4 21 </u>
1 -4 -21 0 <em>remainder is 0 so (x + 1) is a factor</em>
(x - 1)(x + 1)(x² - 4x - 21)
Then, factor the third polynomial
(x - 1)(x + 1)(x + 3)(x - 7)
Now, set each factor equal to zero and solve each one.
(x - 1) = 0 ⇒ x = 1
(x + 1) = 0 ⇒ x = -1
(x + 3) = 0 ⇒ x = -3
(x - 7) = 0 ⇒ x = 7
19/20. All you have to do is divide them both of them by five and then you get your answer
Answer:
divide 21 by 12 then multiply by 10 = $17.5
The vertex form is y=a(x-h)²+k
the vertex is (h,k)
so
y=-1(x-2)²+3
compare to
y=a(x-h)²+k
2=h and 3=k
the vertex is (2,3)
4th option
