Answer:
Step-by-step explanation:
Remember:
Given the equation , you need to solve for the variable "x" to find its value.
You need to square both sides of the equation:
Simplifying, you get:
Factor the quadratic equation. Find two numbers whose sum be 7 and whose product be -8. These are: -1 and 8:
Then:
Let's check if the first solution is correct:
(It checks)
Let's check if the second solution is correct:
(It does not checks)
Therefore, the solution is:
Given:
The height h of an object after t seconds is
The height of a neighboring 50-foot tall building is modeled by the equation h=50.
The time (t) when the object will be at the same height as the building is found to be t = –2 and t = 5.
To find:
The statement which describes the validity of these solutions.
Solution:
We have,
Here, t is the time in seconds.
For t=-2,
For t=5,
So, the value of h is 50 at t=-2 and t=5.
We know that time is always positive so it cannot be negative value. It means t=-2 is not possible.
The solution t = 5 is the only valid solution to this system since time cannot be negative.
Therefore, the correct option is C.