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:

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:

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:

Substitute:

Solve for <em>k</em>. Simplify:

Solve:

Thus, our answer is indeed A.
We can’t graph for you here, sorry
The answer is in the image. We need 3.625 gallons to fill the tank.
Answer:
First one: 5x3(0.75)2t
and fourth one: 0.05x500(0.005)t
Step-by-step explanation:
In order to have an exponencial decay, the rate of the exponencial function needs to be lesser than 1.
The rate is the value between parenthesis, so in the first equation, the rate is 0.75, so this is an exponencial decay.
The second equation has rate = 2.4, so this is not an exponencial decay.
The third equation has rate = 1.04, so this is not an exponencial decay.
The fourth equation has rate = 0.005, so this is an exponencial decay.