The points (-6,r) and (2,5) lie on a line with slope -1/4. Find the missing coordinate r.

Answer:
r = 7
Step-by-step explanation:
Calculate the slope using the slope formula then equate to - [tex]\frac{1}{4}[/tex]
m = [tex]\frac{y_{2}-y_{1} }{x_{2}-x_{1} }[/tex]
with (x₁, y₁ ) = (- 6, r ) and (x₂, y₂ ) = (2, 5 )
m = [tex]\frac{5-r}{2-(-6)}[/tex] = [tex]\frac{5-r}{2+6}[/tex] = [tex]\frac{5-r}{8}[/tex] , then
[tex]\frac{5-r}{8}[/tex] = - [tex]\frac{1}{4}[/tex] ( multiply both sides by 8 to clear the fractions )
5 - r = - 2 ( subtract 5 from both sides )
- r = - 7 ( multiply both sides by - 1 )
r = 7
Answer:
[tex]\displaystyle 7[/tex]
Step-by-step explanation:
[tex]\displaystyle \frac{-y_1 + y_2}{-x_1 + x_2} = m\\ \\ \frac{-r + 5}{6 + 2} = m \Rightarrow \frac{-r + 5}{8} \hookrightarrow -\frac{2}{8} = -\frac{1}{4} \\ \\ \boxed{7 = r}[/tex]
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