Question

Write in slope-intercept form the equation of the line containing the point (-1, 2) and parallel to the given line y = 2x + 4.

Answer 1

y = 2x + 4

Explanation:

`P=(-1,\,2)\quad\implies\quad x_p=-1\,,\quad y_p=2`

The slope-intercept form the equation of the line:

y = mx + b

Two lines are parallel if they hav the same slope, so

m = 2 ⇒ y = 2x + b

The line goes through P so:
`y_p=2x_p+b`

2 = 2(-1) + b

2 = -2 + b

b = 4

so it's the same line as given one:

y = 2x + 4