Write an equation in slope-intercepr form of the line that passes through the given point and is parallel to the graph of the given equation.

Question

(-1,3); y=2x-8

Answer 1

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

 

Since it's parallel to the line they give, it has to have the same slope.  The slope of y=2x-8 is 2, so now we know what m is.

 

So the equation will look like y = 2x + b.  We just have to find b.

 

To do that, remember that if a point is on a line, it means that it satisfies the equation.  So plug the values for the point it passes through into the equation and see what you get:

 

y = 2x + b

3 = 2(-1) + b

3 = -2 + b

 

Add 2 to both sides:

5 = b

 

So the equation is y = 2x + 5

 

To check, plug the values for the point back in and see if it works:

 

3 = 2(-1) + 5

3 = -2 + 5

3 = 3

 

Success!