Question

Find the equation of the line that is parallel

to the line y = 3x + 9 and passes
through the point (2,1) Write the
equation in slope-intercept form.

Answer 1

y = 3x - 5

Explanation:

The equation of a line in slope- intercept form is

y = mx + c ( m is the slope and c the y- intercept )

y = 3x + 9 ← is in slope- intercept form

with slope m = 3

Parallel lines have equal slopes, then

y = 3x + c ← is the partial equation

To find c substitute (2, 1) into the partial equation

1 = 6 + c ⇒ c = 1 - 6 = - 5

y = 3x - 5 ← equation of parallel line