Created by rory.examtime almost 6 years ago
A linear equation is an algebraic equation with two variables (x & y) which refers to a line in the co-ordinate plane.
There are two common forms of linear equations:
1. y = mx + c
- m and c are constants- m is equal to the slope of the line.
2. ax + by + c = 0
- a, b and c are constants
If we know the equation of a line, we can plot it on the co-ordinate plane.
This is done by subbing a value for x (usually 0) to find a corresponding y-value, and vice versa.
x represents the horizontal co-ordinate
y represents the vertical co-ordinate
E.g :y = 4x + 7
Let x = 0
y = 7
=> (0, 7) is on the line
Then, let y = 0
0 = 4x + 7
4x = -7
x = -4/7
=> (-4/7, 0) is also on the line.
Now that we have two points on the line, we can plot it by drawing a straight line which passes through both.