Answer:
158 cases
Step-by-step explanation:
Given tbe quadratic regression model :
y = -2x^2 + 40x + 8
y = number of cases of a new disease
x = number of years
The predicted number of cases of a new disease in 15 years can be calculated thus ;
Put x = 15 in the equation ;
y = -2(15)^2 + 40(15) + 8
y = - 2 * 225 + 600 + 8
y = - 450 + 600 + 8
y = 158
158 cases
One way to go about this is to first list everything we know in the form of variables. This will make it easier to see how these numbers correlate instead of trying to remember formulas to plug these numbers into.
TimeA = 2.4h (time of Car A to travel)
TimeB = 4h (time of Car B to travel)
SpeedA = SpeedB + 22mph (Speed of Car A<span>)
</span>SpeedB = SpeedA - 22mph (Speed of Car B<span>)
</span>Distance = x (the distance traveled by each car)
We are looking for SpeedA. How can we find this? Well, we know that speed multiplied by time is equal to distance, so let's start there.
SpeedA * 2.4h = x
<span>(SpeedB + 22mph) * 2.4h = x
</span>(2.4h * SpeedB) + 52.8miles = x
We also know that:
SpeedB * 4h = x
Since both of these equations are equal to x, we can combine them:
SpeedB * 4h = x = <span>(2.4h * SpeedB) + 52.8miles
</span>SpeedB * 4h = <span>(2.4h * SpeedB) + 52.8miles
</span>1.6h * Speed B = 52.8miles
SpeedB = 52.8/1.6 mph = 33 mph
<span>SpeedA = SpeedB + 22mph = 33mph + 22mph = 55mph
</span>
Therefore, Car A was traveling at 55mph.
The equation for a parabola with vertex (h, k) and vertical scale factor "a" is
y = a(x -h)² + k
One parabola with vertex (6, 9) is
y = (x-6)² +9
Answer:
c= -2.5-0.5d
Step-by-step explanation:
15=-3(2c+d)
15=-6c+-3d
15+3d=-6c
-2.5-0.5d=c
