Question

What is an equation of the line that passes through the point (8,-1) and (4,-1)?

Answer 1

Answer:

Step-by-step explanation:

We can start with the general form of the equation for a straight line (may we assume this is a straight line?): y=mx+b. m is the slope (the rate of change of y for a change in x) and b is the y-intercept (the value of y when x=0).

Slope is the Rise of the line (the y axis) and Run is the change in the x axis to create the change in y. The slope is the Rise/Run, which we can find if we have two points on the line.

(8,-1) and (4,-1) will gives us the information to find the slope, m. The Rise is the change in y:

(-1-(-1)) = 0 !!!! It doesn't matter what the change in x is - the slope will be zero. It it weren't zero, it would be calculated as (8 - 4) or 4. The Rise/Run is 0/4 or 0 for this line. It is a flat line! The equation:

y=mx+b

y = 0x + b

y = b

This tells us the value of y will be the y-intercept, which is -1. Y is the same regardless of the value of x.

The equation is y=-4