10.1 Linear Equations
What is a linear equation? To begin with graphically, anything that produces straight line on a graph has got a linear equation behind it.
All of the following have linear equations behind them:
x and y are the variables that are plotted on x and y axis, m is the gradient and c is the y-intercept. These will become clearer when we look at examples below.
Before looking into examples, note the following formula we will use to work out m and c:
James sells laptops. If he sells 10 laptops his profit is $1,300 and when he sells 25 laptops his profit is $3,550. You are told this follows linear equation. Draw this on a graph. What is the equation of his profit? Are there any limitations?
What is the gradient and y-intercept of following linear equations?
- What is the y-intercept of blue line?
- Is gradient of red line positive or negative?
- Between blue and green line, which one has higher gradient?
- What is the gradient of yellow line?