(3 - i) + (1 - 2i)
= 3 + 1 - i - 2i
= 4 - 3i
Let x and y be the rate per hour for Mechanic 1 and 2 respectively.
Then,
x+y=205 ---------- (1)
Additionally,
10x+15y = 2500 ------ (2)
Solving equations 1 and 2;
Multiply (1) by 10 and subtract two from the result,
10x+10y = 2050
10x +15 y =2500
----------------------
-5 y = --450 => y = 450/5 = $90
Then,
x= 205-90 = $115
Therefore,
Mechanic 1 charged $115 per hour
Mechanic 2 charged $90 per hour
Because the parabola opens down and the vertex is at (0, 5), we conclude that the correct option is:
y = -(1/8)*x² + 5.
<h3>
Which is the equation of the parabola?</h3>
The relevant information is that we have the vertex at (0, 5), and that the parabola opens downwards.
Remember that the parabola only opens downwards if the leading coefficient is negative. Then we can discard the two middle options.
Now, because the parabola has the point (0, 5), we know that when we evaluate the parabola in x = 0, we should get y = 5.
Then the constant term must be 5.
So the correct option is the first one:
y = -(1/8)*x² + 5.
If you want to learn more about parabolas:
brainly.com/question/4061870
#SPJ1
Answer:
70.56
Step-by-step explanation:
The variance is the standard deviation squared.
σ² = (8.4)² = 70.56
