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A line passes through the points (-3, -1) and (6, -4)
What is the equation of the line?

User Susensio
by
4.6k points

1 Answer

4 votes

Answer:

y = -x/3 - 4/3

Explanation:

Equation of a line

y_2 - y_1 / x_2 - x_1 = y - y_1 / x - x_1

We are provided with Two points

( -3 , -1) and (6 , -4)

x_1 = -3

y_1 = -1

x_2 = 6

y_2 = -4

Inserting the values given into

(y_2 - y_1)/ (x_2 - x_1) = (y - y_1) / (x - x_1 )

-4 - (-1) / 6 - (-3) = y - (-1) / x - (-3)

-4 + 1 / 6 + 3 = y + 1/ x + 3

-3/9 = y + 1 / x + 3

Cross multiply

-3( x + 3) = 9( y + 1)

Open the brackets

-3x - 3 = 9y + 9

Following the equation of a line

y = mx + C

Make y the subject of the formula

-3x - 3 = 9y + 9

-3x - 3 - 9 = 9y

-3x - 12 = 9y

Divide both sides by 9 to get y

-3x - 12 / 9 = 9y / 9

y = -3x - 12 /9

We can separate it

y = -3x /9 - 12 / 9

y = -1x/3 - 4/3

y = -x/ 3 - 4/3

User Dogcat
by
4.5k points