How do you write the equation in point slope form given (8,7), (-2,-4)?

1 Answer
Jun 30, 2016

y+4=11/10(x+2).y+4=1110(x+2). [#pt.(-2,-4) used]

y-7=11/10(x-8).y7=1110(x8). [using #pt.(8,7)

Explanation:

Let the given pts. be A(8,7), B(-2,-4).A(8,7),B(2,4).

Then, by defn., slope of line ABAB is, by defn., (y_B-y_A)/(x_B-x_A)= (-4-7)/(-2-8)=-11/-10=11/10.yByAxBxA=4728=1110=1110.

Pt. B(-2,-4)B(2,4) ies on Line ABAB

Hence, eqn. of line AB,AB, in slope-pt. form, using pt.B(-2,-4),B(2,4), is :

y-(-4)=11/10(x-(-2)),y(4)=1110(x(2)), i.e., y+4=11/10(x+2).y+4=1110(x+2).

One can choose pt.A(8,7)A(8,7) to get the eqn. y-7=11/10(x-8).y7=1110(x8).