Answer: -5, 3, 4 + 1,4-i (option 2)
Step-by-step explanation:
The roots of an equation are the x values for f(x) = 0. Therefore to find the roots of the equation, you first set the function to 0 and then solve for the values of x.
since f(x) = -(x² + 2x - 15) (x² + 8x + 17)
0 = -(x² + 2x - 15) (x² + 8x + 17)
∴ either -x² - 2x + 15 = 0 OR x² + 8x +17 = 0
when -x² - 2x + 15 = 0
-x² - 5x + 3x + 15 = 0
(x - 3 ) (-x - 5) = 0
⇒ x = 3 or x = -5
when x² + 8x +17 = 0
= 0 OR 
= 0 (using the quadratic equation)
⇒ x = 4 + i or x = 4 - i
∴ the complete list of roots is -5, 3, 4 + 1,4-i (option 2)
Answer: c = 1.59 * a
Step-by-step explanation:
You got the answer correct.
Part (a)
<h3>Answer:
2(2.4+w) = 14.2</h3>
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Explanation:
L = 2.4 = length
W = unknown width
The perimeter of any rectangle is P = 2(L+W)
We replace L with 2.4, and replace P with 14.2 to get 14.2 = 2(2.4+w) which is equivalent to 2(2.4+w) = 14.2
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Part (b)
<h3>Answer:
w = 4.7</h3>
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Explanation:
We'll solve the equation we set up in part (a)
2(2.4+w) = 14.2
2(2.4)+2(w) = 14.2
4.8+2w = 14.2
2w = 14.2-4.8
2w = 9.4
w = 9.4/2
w = 4.7
The width must be 4.7 cm.
