Question

Given the points (-4,r) and (-8,3) find the value of r that results in a slope of -10

Answer 1

r = -37

Explanation:

Step 1: Write out what is known

• Points are (-4,r) and (-8,3)
• Slope = m = -10
• 
  `m=(y_(2)-y_(1))/(x_(2)-x_(1))`

Step 2: Set up an equation to solve for r

• 
  `m=(3-r)/(-8-(-4)) =-10`

Step 3: Solve for r

1. 
   `(3-r)/(-8-(-4)) =-10\\`
2. 
   `(3-r)/(-8+4) =-10`
3. 
   `(3-r)/(-4) =-10`
4. 
   `(-4)(3-r)/(-4) =-10(-4)`
5. 
   `3-r=40`
6. 
   `-r=37`
7. 
   `r=-37`