2 different possible ways if there is only 2 students.
Answer: Option D.
Step-by-step explanation:
this is a quadratic equation of the form:
y = ax^2 + bx + c
First, things you must see.
The graph opens up, so we must have thata a is greater than zero, so we can discard the first option.
Second, we can see that the vertex is located in x ≈ 70
The vertex of a quadratic equation is: x = -b/2a
so we have:
70 = -b/2a
let's try our options and see if we can discard other:
B:
-b/2a = 69.9/2 = 34.95
we can discard this option.
C:
-b/2a = 78/2 = 39 we can discard this option.
D:
-b/2a = 69.9/2*0.5 = 69.9
This is the only one that fits, so this is the correct option.
Step-by-step explanation:
- 4x2 - 80x - 400
- 4x2 - 40x - 40x - 400
-4x( x + 10) - 40(x + 10)
(x + 10) and ( - 4x - 40) are the factors
