Answer:
It's like solving a quadratic, but in reverse, and in this case you'll arrive at x2+x−12=0
Explanation:
We're going to go "backwards" with this problem - normally we're asked to take a quadratic equation and find the roots. So we'll do what we normally do, but in reverse:
Let's start with the roots:
x=3, x=−4
So let's move the constants over with the x terms to have equations equal to 0:
x−3=0, x+4=0
Now we can set up the equation, as:
(x−3)(x+4)=0
We can now distribute out the 2 quantities:
x2+x−12=0
Answer:
The number of persons using the elevator at any hour is never going to be less that 15.
Step-by-step explanation:
To solves this you have to suppose that there are at least 15 persons on the elevator, and the equation is converted into an inequation:
Now you transform the inequation back to an equation to solve it:
![t^2-10t+25=0](https://tex.z-dn.net/?f=t%5E2-10t%2B25%3D0)
You need to know if there is any negative solution for the equation, to do this you can use the discriminant for a quadratic equation:
![D=b^2-4ac](https://tex.z-dn.net/?f=D%3Db%5E2-4ac)
In this case, you have a=1, b=-10, c=25
![D= (-10)^2-4(1)(25)\\D=0](https://tex.z-dn.net/?f=D%3D%20%28-10%29%5E2-4%281%29%2825%29%5C%5CD%3D0)
Since the discriminant is 0 and a<0 the equation always is going to be positive. Therefore, the number of persons using the elevator at any hour is never going to be less than 15.
Well, all you have to do is divide the length by 2. Then multiply that by 30. 70 divided by 2 is 35, and 35x30 is 1050.
Answer:
<5 and <7= 56 degrees
Step-by-step explanation:
for <5: 180-124=56
<7 is equal to <5
Brainliest Plz?