Question

Write the equation of a line in slope-intercept form that goes through the points (1, 1)and (−1,−9

Answer 1

y = 5x - 4

Explanation:

The line goes through the points (−1,−9) and (1, 1).

We can see quickly that x increases by 2 and y increases by 10. Thus, the slope of this line is

m = rise / run = 10 / 2 = 5.

Using the slope-intercept equation for a straight line, y = mx + b, we get

1 = 5(1) + b. Thus, b = -4, and the desired equation is

y = 5x - 4