Question

I got these wrong could anyone tell me how to do these ?

Answer 1

Answer:

  15. y -13 = -2(x +7)

  16. y -6 = (-3/4)(x +4)

  17. y +11 = 4(x +5)

  18. y -8 = (-5/3)(x +6)

Step-by-step explanation:

It looks to me like you have the right idea in each case, but have made mistakes with signs or parentheses. Neatness and attention to detail count for a lot.

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You obviously know that the point-slope form of the equation of a line with slope m through point (h, k) is ...

  y -k = m(x -h)

In problems 15 and 16, the given slopes are negative. Your equations seem to have missed that fact.

15. m = -2, (h, k) = (-7, 13).  y -13 = -2(x +7)

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16. m = -3/4, (h, k) = (-4, 6).  y -6 = (-3/4)(x +4)

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It is clear you know that slope is computed as ...

  m = (y2 -y1)/(x2 -x1)

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17. m = (1 -(-11))/(-2-(-5)) = 12/3 = 4; (h, k) = (-5, -11).  y +11 = 4(x +5)

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18. m = (-7-8)/(3-(-6)) = -15/9 = -5/3; (h, k) = (-6, 8).  y -8 = (-5/3)(x +6)