The slope of a line through points [tex]A(x_1, y_1)[/tex] and [tex]B(x_2, y_2)[/tex] is :
[tex]\displaystyle{ \frac{y_2-y_1}{x_2-x_1} [/tex]
or
[tex]\displaystyle{ \frac{y_1-y_2}{x_1-x_2} [/tex],
it is the same thing, BUT it it always y's over x's and always in the same order of 1 and 2:
don't write: [tex]\displaystyle{ \frac{y_1-y_2}{x_2-x_1} [/tex]
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The slope of the line through the points (-23, -17) and (-13, -7) is :
[tex]\displaystyle{ \frac{-17-(-7)}{-23-(-13)}= \frac{-17+7}{-23+13}= \frac{-10}{-10}=1 [/tex]
Answer: 1
