Question

What is the equation of the line that is parallel

to the line y = 2x - 1 and passes through the
point (2, 7)?

Answer 1

y = 2x + 3

Explanation:

1. Approach

The line y = 2x -1 is written in slope-intercept form, essentially; y = mx + b, where "m" is the slope, and "b" is the y-intercept. If two lines are parallel, then they both have the same slope. So one simply has to substitute in a point on the line to find out what the y-intercept is, and assemble the equation.

2. Slope

As mentioned above, two parallel lines have the same slope. Hence the slope of the line that one is trying to find the equations of is 2.

3. y-intercpet

Substitute in the point that is given, and solve for the y-intercept.

y = mx + b

y = 2x + b

7 = 2(2) + b

7 = 4 + b

3 = b

4. Assembling what one knows

The equation of the line is;

y = 2x + 3

Were 2 is the slope, and 3 is the y-intercept.

Answer 2

y= 2x + 3

Explanation:

To have a parallel line they need to have the same slope.

Then you need to plot the point (2,7).

A slope of 2x means that it goes up 2 y values for every x value it goes up by. So to find the y-intercept, you need to go down 2 x values. Meaning you need to subtract 4 y values. (0,3).

y= (slope) + y-intercept