D. Umm explanation you’re not asking for who but the number of students.
Answer:
Plot these points
(-3,0)
(-5,0)
(-4,1)
(-2,-3)
(-6,-3)
Step-by-step explanation:
Let find the zeros of the equation.
We can factor this equation.
Factor out the -1.
Factor using AC method
Set all the terms equal to zero.
So our x intercepts are -3,0 and -5,0.
To find our vertex, apply the -b/2a.
Then
Substitute-4 for x.
So our vertex is at (-4,1).
Find some other points like -2 and -6.
To find -2, substitute-2 into the quadratic.
So -2,-3.
Since y=-4 is the axis of symmetry
-6,-3
Answer:
The initial speed is approximately 104.3 km
Step-by-step explanation:
Let Distance = 240 km
Time = ?
Speed =
Since
Speed = Distance/Time
Distance = Speed × Time
When arrival is late:
240 = S×T
When arrival is on time:
240 = (S+5)×T2
But 40minutes = 2/3 hours
So,
T2 = T - 2/3
240 = (S+5)×(T - 2/3)
240 = ST - 2S/3 + 5T - 10/3
ST - 2S/3 + 5T = 240 + 10/3
S(T - 2/3) + 5T = 730/3
S(T - 2/3) = 730/3 - 5T
S = (730/3 - 5T)/(T - 2/3)
But 240 = ST
S = 240/T
240/T = (730/3 - 5T)/(T - 2/3)
(T - 2/3)/T = (730/3 - 5T)/240
1 - 2/3T = 730/720 - 5T/240
1 + 73/72 = (2/3 + 5/24)T
145/72 = (7/8)T
T = 145/72 × 8/7
= 1160/504
T = 145/63
S = 240/S
= 240×63/145
= 3024/29
≈ 104.3km