Question

How do you write an equation in slope intercept form given a slope and a x-intercept?

Answer 1

What is x-intercept? It is such an argument (x-value) where y-value equals 0. In equations you would tell that it is root of the equation.

In general formula `y = mx+b` you insert known information, where `m` is a slope (or gradient) and `b` is free-term (or y-intercept - such an value where function cuts y-axis, so point (0, b) ).

Let us take example. You are given slope - it is 2. And you know that your x-intercept is equal 3. Therefore, you know that when `x = 3`, `y=0`.

Let us use that information. You know that you may write every linear function like that: `y = mx+b`.
Let us insert values: `0 = 2*3+b`
Our unknown is `b`, free term. Let us isolate it:
`b=-6`.
And after all, we must insert our `b` value back into equation: `y = 2x - 6`.