Equation of the Line Lesson
I
After going through this lesson, you are expected to find the equation of a
line given (a) two points, (b) the slope and a point and (c) the slope and its
intercepts
From the given linear equation, we can determine 2 points that will satis-
fy the equation. Also we can determine the slope and the y- intercept so as the
x and y intercepts.
Example: Given - 2x + y = 6
Find: a. two points that will satisfy the equation
(b) slope and y-intercept
(c) x and y intercept
Solution:
(a) -2x + y = 6
If x = -1
If y = 2
-21-1) + y = 6
- 2x + 2 = 6
2 + y = 6- y = 4
-2x = 4-x= -2
The point is (-1,4)
The point is (-2, 2)
(b) Change the equation to slope intercept form : y = 2x + 6
Therefore the slope m = 2 and the y-intercept b = 6
(c) Find the and y intercept of -2x + y = 6
Let x = 0, -2(0) + y = 6; y = 6. the intercept is (0,6)
Let y = 0, -2x + 0 = 6; -2x = 6, X = -3, the y intercept is (-3,0)
Learning Task 1 : From the given equation of the line a) find two points that will
satisfy the equation, b) the slope and the y intercepts and c) the x and y-
intercepts.
2.
3y - X9
1. 3x + 2y = 5