SOLUTION: Find a linear function h such that h(-1)=-5 and h(7)=-6. What is h(3/2)?

Algebra ->  Functions -> SOLUTION: Find a linear function h such that h(-1)=-5 and h(7)=-6. What is h(3/2)?      Log On


   



Question 413665: Find a linear function h such that h(-1)=-5 and h(7)=-6. What is h(3/2)?
Answer by Edwin McCravy(20055) About Me  (Show Source):
You can put this solution on YOUR website!
Find a linear function h such that h(-1)=-5 and h(7)=-6. What is h(3/2)?

First you interpret it as this problems:

Find the equation of the line that passes through the two points
(-1,-5) and (7,-6).  

Use the slope formula: 


     y2 - y1      (-6) - (-5)      -6 + 5     -1 
m = ---------- = -------------- = -------- = ----- = -1%2F8
     x2 - x1        7 - (-1)        7 + 1      8

Then use the point-slope formula:

y - y1 = m(x - x1)

y - (-5) = -1%2F8(x - (-1) )

   y + 5 = -1%2F8(x + 1)

   y + 5 = -1%2F8x - 1%2F8

       y = -1%2F8x - 1%2F8 - 5

       y = -1%2F8x - 1%2F8 - 40%2F8

       y = -1%2F8x - 41%2F8

Now replace y by h(x)
 
    h(x) = -1%2F8x - 41%2F8

That's the first part.

What is h(3%2F2)?

Substitute 3%2F2 for x in

    h(x) = -1%2F8x - 41%2F8

    h(3%2F2) = -1%2F8%283%2F2%29 - 41%2F8

    h(3%2F2) = -3%2F16 - 41%2F8 

    h(3%2F2) = -3%2F16 - 82%2F16

    h(3%2F2) = -85%2F16  
  
Edwin