Question

Find the equation of the linear function 'g' going through (20,5) and (-5,-8). Use 'u' for your input variable.

g(u)=

Answer 1

Slope

• m=(-8-5)/-5-20
• m=-13/-25
• m=13/25

Equation in point slope form

• y-5=13/25(x-20)
• y=13/25x-13/25(20)+5
• y=13/25x+21/5

g(u)=13/25u+21/5

Answer 2

• See below

Explanation:

Use the slope-intercept form, which will be in this case:

• g(u) = mu + b, where m is the slope, b is the y- intercept

Find the slope:

• 
  `m=(y_2-y_1)/(x_2-x_1)`
• 
  `m=(-8-5)/(-5-20)=(-13)/(-25)=13/25`

Find the value of the y-intercept:

• 
  `5=1/25*20+b`
• 
  `b=5-4/5=21/5`

The equation is:

• 
  `g(u)=(13)/(25) u+(21)/(5)`