Question

Write an equation of the line that passes through (-1, 3) and is parallel to the line y = -3x + 2

Answer 1

y -3 = -3(x +1)

Explanation:

You want an equation for the line parallel to y=-3x+2 through the point (-1, 3).

Slope-intercept form

The given line is written in slope-intercept form:

y = mx +b . . . . . . . where m is the slope and b is the y-intercept

Matching your equation to this form, we see that ...

• m = -3
• b = 2

The parallel line will have the same slope: m = -3.

Point-slope form

Another form of the equation for a line is "point-slope form." That is ...

y -k = m(x -h) . . . . . . line with slope m through point (h, k)

Perhaps you can see this would be useful for writing the equation of a line with slope -3 through the point (-1, 3).

y -3 = -3(x +1) . . . . . . . line with slope -3 through point (-1, 3)