Example

Finding the Equation of a Line Parallel to y=2x3y = 2x - 3 Through (2,1)(-2, 1)

To find the equation of a line parallel to y=2x3y = 2x - 3 that passes through the point (2,1)(-2, 1), apply the five-step parallel-line procedure and write the result in slope-intercept form.

Step 1 — Find the slope of the given line. The equation y=2x3y = 2x - 3 is already in slope-intercept form, so the slope is m=2m = 2.

Step 2 — Find the slope of the parallel line. Parallel lines share the same slope, so m=2m_{\parallel} = 2.

Step 3 — Identify the point. The given point is (x1,y1)=(2,1)(x_1, y_1) = (-2, 1).

Step 4 — Substitute into the point-slope form yy1=m(xx1)y - y_1 = m(x - x_1):

y1=2(x(2))y - 1 = 2(x - (-2))

Simplify inside the parentheses:

y1=2(x+2)y - 1 = 2(x + 2)

Distribute:

y1=2x+4y - 1 = 2x + 4

Step 5 — Write in slope-intercept form by adding 1 to both sides:

y=2x+5y = 2x + 5

The equation of the parallel line is y=2x+5y = 2x + 5. Both lines have slope 22, confirming they are parallel, but they have different yy-intercepts (3-3 vs. 55), so they are distinct lines that never intersect.

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Updated 2026-04-21

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