Answer:
Nicole is correct
Step-by-step explanation:
by multiplying the first equation by 3 it becomes:
3x + 6y =21
this can cancel the -3x in the second equation when adding them together
Answer:
-1 and 30
Step-by-step explanation:
5-2=3 3-2=1 1-2= -1
21+3=24 24+3=27 27+3= 30
Firs movie was 100min
Second movie was 1h and 55min
1h is 60min
So 60+55=115
Ans:second movie was longer by 15min
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:

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:

In this case, you have a=1, b=-10, c=25

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.
C, this class is really hard, if u need tutoring contact me