Answer:
Step-by-step explanation:
Let x represent the length of the rectangle. The the width is (4x+2) and the area is ...
x(4x+2) = 342
2x² +x - 171 = 0 . . . . . divide by 2, rearrange to standard form
(2x +19)(x -9) = 0 . . . factor
x = -19/2 or +9 . . . . . the length is the positive solution: 9
(4x+2) = 4(9) +2 = 38 . . . . find the width from the length
The length of the rectangle is 9 meters. The width is 38 meters.
Answer: 1) (-∞, -6) U (-3, ∞)
2) (-∞, -4) U (2, ∞)
3) (-∞, -3) U (8, ∞)
<u>Step-by-step explanation:</u>
Find the zeros. Since the a-value is positive, the curve will be positive to the left of the leftmost zero and to the right of the rightmost zero. + - +
←---|----|--→
1) y = x² + 9x + 18
y = (x + 3)(x + 6)
0 = (x + 3)(x + 6)
0 = x + 3 0 = x + 6 + -- +
x = -3 x = -6 ←------|-----------|--------→
-6 -3
Positive Interval: (-∞, -6) U (-3, ∞)
2) y = x² + 2x - 8
y = (x + 4)(x - 2)
0 = (x + 4)(x - 2)
0 = x + 4 0 = x - 2 + -- +
x = -4 x = 2 ←------|-----------|--------→
-4 2
Positive Interval: (-∞, -4) U (2, ∞)
3) y = x² - 5x - 24
y = (x + 3)(x - 8)
0 = (x + 3)(x - 8)
0 = x + 3 0 = x - 8 + -- +
x = -3 x = 8 ←------|-----------|--------→
-3 8
Positive Interval: (-∞, -3) U (8, ∞)
Yes it's correct..........