Answer:
A
Step-by-step explanation:
Recall that for a quadratic equation of the form:
The number of solutions it has can be determined using its discriminant:
![\Delta = b^2-4ac](https://tex.z-dn.net/?f=%5CDelta%20%3D%20b%5E2-4ac)
Where:
- If the discriminant is positive, we have two real solutions.
- If the discriminant is negative, we have no real solutions.
- And if the discriminant is zero, we have exactly one solution.
We have the equation:
![2x^2+5x-k=0](https://tex.z-dn.net/?f=2x%5E2%2B5x-k%3D0)
Thus, <em>a</em> = 2, <em>b</em> = 5, and <em>c</em> = -<em>k</em>.
In order for the equation to have exactly one distinct solution, the discriminant must equal zero. Hence:
![b^2-4ac=0](https://tex.z-dn.net/?f=b%5E2-4ac%3D0)
Substitute:
![(5)^2-4(2)(-k)=0](https://tex.z-dn.net/?f=%285%29%5E2-4%282%29%28-k%29%3D0)
Solve for <em>k</em>. Simplify:
![25+8k=0](https://tex.z-dn.net/?f=25%2B8k%3D0)
Solve:
![\displaystyle k = -\frac{25}{8}](https://tex.z-dn.net/?f=%5Cdisplaystyle%20k%20%3D%20-%5Cfrac%7B25%7D%7B8%7D)
Thus, our answer is indeed A.
Answer:
D
Step-by-step explanation:
R(x) = -x^2+122x+400
Answer:
<em><u>Lines are perpendicular to each other .</u></em>
Step-by-step explanation:
Standard equation of line is : y = mx + c, Where m represents the slope
Given Equations :
![y = -5x + 1\\\\Slope , m_1 = -5](https://tex.z-dn.net/?f=y%20%3D%20-5x%20%2B%201%5C%5C%5C%5CSlope%20%2C%20m_1%20%3D%20-5)
![y = \frac{1}{5}x +1\\\\Slope, m_2 = \frac{1}{5}](https://tex.z-dn.net/?f=y%20%3D%20%5Cfrac%7B1%7D%7B5%7Dx%20%2B1%5C%5C%5C%5CSlope%2C%20m_2%20%3D%20%5Cfrac%7B1%7D%7B5%7D)
Two lines are parallel if the slope of the lines are same.
Two line are perpendicular if the product of the slope = - 1
Clearly slopes are not equal , therefore the lines are not parallel.
product of the slope is - 1, therefore the lines are perpendicular.
![m_1 \times m_2 = -5 \times \frac{1}{5} = - 1](https://tex.z-dn.net/?f=m_1%20%5Ctimes%20m_2%20%3D%20-5%20%5Ctimes%20%5Cfrac%7B1%7D%7B5%7D%20%3D%20-%201)
Answer:
82°
Step-by-step explanation:
Answer:
18 inches
Step-by-step explanation:
volume = lenght * width * depth
let the depth be x
32400=60*30*x
x=32400/(60*30)
x=32400/1800
x=18