Answer:

Explanation:
The equation for a straight line is

where m is the gradient and c is the y-intercept.
To have the full equation, we need to find m and c values.
To find m, the formula is

By substituting the two points (4,1) and (3,-1) into the formula, we get:

Now we have

To solve for c, substitute any of the two points in to the equation. Let's say we insert (4,1) into the equation:

Therefore, the full equation is

Pro tip:
You can always substitute (4,1) or (3,-1) to check if the equation is correct.