SOLUTION: Write the slope-intercept equation for the line that passes through (1, -9) and (3, -1).

Algebra ->  Numeric Fractions Calculators, Lesson and Practice -> SOLUTION: Write the slope-intercept equation for the line that passes through (1, -9) and (3, -1).       Log On


   

Question 387847: Write the slope-intercept equation for the line that passes through (1, -9) and (3, -1).
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!


Hi

Using the point-slope formula, m+=%28y%5B2%5D+-+y%5B1%5D%29%2F%28x%5B2%5D+-+x%5B1%5D%29

  (1, -9) and (3, -1). 

 m = -1 -(-9)  / 3-1  = 8/2 = 4

 m = 4

Using the standard slope-intercept form for an equation of a line y = mx + b  where m is the slope and b the y-intercept.  

 y = 4x + b using ordered pair pt(3,-1) to solve for b

 -1 = 4*3 + b

 -13 = b

 y = 4x - 13