What is an equation of the line through (0, –3) with slope 2/5

Answer 1

Since you know the slope and you know one point, all you have to do is plug the slope and the coordinates into the slope-intercept form and solve for b.

y = mx + b

y=-3 x=0 and m=2/5

-3 = (2/5)0 + b

Since 2/5(0) is 0, b must be -3.

So the equation is y = (2/5)x - 3

You can check your answer by finding another point on the line and verifying that the equation works for that point, as well. Add the slope to the given point and you get ( 5 , -1 )

-1 = (2/5)5 - 3

-1 = 2 - 3

-1 = -1 So you know your answer is correct

Answer 2

Hi Alyssa H.,

The equation of a line is written in the form of y=mx+b. From the information given we can use:

(y - y₁) = m*(x - x₁); with (x₁, y₁) as (0, -3); and m = 2/5 from the problem.

(y - -3) = 2/5*(x - 0);

y + 3 = 2x/5

y = 2x/5 - 3, answer.

I hope this helps, Joe.