The points (3,r) and (6,-4) lie on a line with slope -1 . Find the missing coordinate r

Question

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Answer 1

Use point-slope form: y₂ - y₁ = m(x₂ - x₁)

Points are (3, r) and (6, -4); m = -1

-4 - r = -1(6 - 3)

-4 - r = -6 + 3 = -3 -4 + 3 = r

r = -1

Answer 2

The slope equation iis:

Plug in m = -1, x₁ = 3, y₁ = "r", x₂ = 6, y₂ = -4:

-1 = (-4 - r)/(6 - 3)

-1 = (-4 - r)/3

-1(3) = -4 - r

-3 = -4 - r

-3 + 4 = -r

1 = -r

r = -1