Question

Write an equation, in point-slope form, for the line that goes through points (4,4) and (-4,-1).

A.) Y= 5/8x - 3 1/2
B.) Y= 4x + 1 1/2
C.) Y= 5/8x + 1 1/2
D.) Y= 4X - 3 1/2

Answer 1

C.) Y= 5/8x + 1 1/2

Explanation:

To write the equation of a line, calculate the slope between points (4,4) and (-4,-1). After, substitute the slope and a point into the point slope form.

`m = (y_2-y_1)/(x_2-x_1) = (4--1)/(4--4)= (5)/(8)`

Substitute m = 5/8 and the point (4,4) into the point slope form.

`y - y_1 = m(x-x_1)\\y -4 = (5)/(8)(x-4)\\y-4 = (5)/(8)x - (20)/(8) \\\y = (5)/(8)x - 2{1}{2} + 4 \\ y = (5)/(8)x + 1(1)/(2)`