Answer:
we know that,
y-y1=m(x-x1)
or, y-1=-3(x-5)
or, y-1=15-3x
or 3x+y-16=0 is the required equation
 
        
             
        
        
        
Answer:
i)W = 2500 / T
ii)  W = 500 Tons
iii) grad W(10°) = - 25î
iv) The formulation is not practical
Step-by-step explanation:
i)  Write an equation describing the use of coal
As use of coal is inversely proportional to the average monthly temperature
if  W is use of coal in tons/per month then
W(t)  =   k / T              where k is a constant of proportionality and T is the average temperature in degrees. We have to determine k from given conditions
k  =  ??   we know that when   T  =  25°    W = 100 tons  the by subtitution
W = k/T           100  =  k /25       k  =  2500 Tons*degree
Then final equation is:
W = 2500 / T
ii) Find the amount of coal when T = 5 degrees
W = 2500 / 5
W = 500 Tons
iii)
The inverse proportionality implies that W will decrease as T increase.
The vector gradient of W function is:
grad W  = DW(t)/dt î   
grad W  = - 2500/T² î
Wich agrees with the fact that W is decreasing.
And when T = 100°
grad W(10°) =  - 2500/ 100 î      ⇒  grad W(10°) = - 25î
iv) When T =  0  The quantity of coal tends to infinite and the previous formulation is not practical
 
 
        
             
        
        
        
The y-intercept on the x-y plane is (0, -9).
<h3 /><h3>How to get the y-intercept?</h3>
To get the y-intercept we just need to evaluate in x = 0.
Here we have:
y = 6*(x - 1/2)*(x + 3)
Evaluating the given equation in x = 0 we get:
y = 6*(0 - 1/2)*(0 + 3) = -9
Then the y-intercept on the x-y plane is (0, -9).
If you want to learn more about y-intercepts:
brainly.com/question/1884491
#SPJ1
 
        
             
        
        
        
Answer:
508.4
Step-by-step explanation:
This is on delta math