Question

What is the slope of the line of this equation: `9x + 8y -13 =0`?

Answer 1

`m=-9/8`

Explanation:

The slope of a line can be found when a linear equation is written in the form:

`y = mx + b`

Where `m` is the slope of the line.

You can get to this form, by algebraically isolating the `y`.

`9x+8y-13=0`

Add `13` to both sides:

`9x+8y=13`

Subtract `9x` from both sides:

`8y=-9x+13" "`(notice the `9x` can go in front of `13`)

Divide both sides by `8`:

`y=-9/8x+13/8`

The slope is the coefficient of the `x` term.

ANSWER: `m=-9/8`

Answer 2

Slope = `-9/8`

Explanation:

The equation of a straight line in slope `(m)` and intercept `(c)` form is: `y=mx+c`

in this example: `9x+8y-13=0` can be written as:

`y= -9/8x+13/8`

Hence the slope of `y` is `-9/8` and the `y-`intercept is `13/8`

The graph of `y` is shown below:
graph{9x+8y-13=0 [-10, 10, -5, 5]}