Im trying to do IXL and I dont understand the way my teacher teaches (ironic right?) the points (-9,-3) and (-2,r) fall on a lin

Question

Im trying to do IXL and I dont understand the way my teacher teaches (ironic right?)

the points (-9,-3) and (-2,r) fall on a line with a slope of 1/7. What is the value of r?
If its not right im gonna report you

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Adela 2 months 2021-07-28T14:35:01+00:00 1 Answers 0 views 0

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    2021-07-28T14:36:31+00:00

    Answer:

    r = – 2

    Step-by-step explanation:

    Calculate the slope m using the slope formula and equate to \frac{1}{7}

    m = \frac{y_{2}-y_{1}  }{x_{2}-x_{1}  }

    with (x₁, y₁ ) = (- 9, – 3) and (x₂, y₂ ) = (- 2, r)

    m = \frac{r+3}{-2+9} , that is

    \frac{r+3}{7} = \frac{1}{7} ( cross- multiply )

    7(r + 3) = 7 ( divide both sides by 7 )

    r + 3 = 1 ( subtract 3 from both sides )

    r = – 2

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Giải phương trình 1 ẩn: x + 2 - 2(x + 1) = -x . Hỏi x = ? ( )