# How do you write an equation in standard form for a line passing through R(3, 3), S(-6, -6)?

##### 1 Answer

*Method 1*.

Notice that the values of X-coordinate and Y-coordinate are equal in two different points.

So, an intelligent guess would be to consider an equation

as the representation of this line.

*Method 2*.

Assume that the equation we are looking for is

where

Substitute the given coordinates into this equation:

Resolve the first equation for

From the latter we derive:

Now find

The above resulted in the equation for our line:

*Method 3*.

Again, looking for an equation in a format

As it's known, the coefficient *slope* of a line that can be calculated as a ratio between increment of *ordinate* (Y-coordinate changes from *abscissa* (X-coordinate changes from

In our case this ratio equal to:

To determine coefficient *abscissa* and *ordinate* of one of the points to get an equation for

from which follows that

So, our equation is