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)
