187,449 views
38 votes
38 votes
Write the equation of the line that passes through the points (2, 7) and (5,-2).

User Erik Giberti
by
3.3k points

2 Answers

11 votes
11 votes
The answer is y=-3x+13
User Saeed Hamed
by
2.5k points
23 votes
23 votes

Answer:

y = -3x + 13

Explanation:

Assuming the line is linear, you can use the point-slope equation of a line.

(y - y) = m (x - x)

The y and x variables come from the points on the line. Points are written in the form (x, y). In the point (2,7), 2 is x and 7 is y.

1. Plug your points in.

(7 - - 2) = m (2 - 5)

2. Solve for m (the slope)

(7 + 2) = m (2 - 5)

(9) = m (-3)

9 = -3m

m = -3

3. Write an equation of the line with the slope you found.

You can write this equation in different forms, but I'll use the slope-intercept form.

y = mx + b

You'll have to find b, the y-intercept. You can plug one of your points in for x and y as well as your slope, m, and solve for b.

7 = -3(2) + b

7 = -6 + b

b = 13

Therefore, the equation is y = -3x + 13

User Yehuda
by
3.3k points