Find three different ways to write the equation that represents the line in the plane that passes through points
(1,2) and (2, −1).

y - 2 = -3(x - 1).

y = -3x + 5.

3x + y = 5.

Step-by-step explanation:

The slope of the line is (-1-2) / (2 - 1)

= -3.

Using the point slope form of the equation of a straight line:

y - 2 = -3(x - 1) This is one way to write it.

Simplifying the above:

y = -3x + 3 + 2

y = -3x + 5. This is another way called the slope-intercept form.

Now we convert this to the standard form:

y = -3x + 5

y + 3x = 5

3x + y = 5.

step-by-step explanation:

1. practice, practice & more practice

2. review errors

3. master the key concepts

do not try to memorise the processes.

4. understand your doubts.

5. create a distraction free study environment

6. create a mathematical dictionary

7. apply maths to real world problems.