Simultaneous Linear Equations Objectives (a)Plot linear equations on a graph (b)Plot two linear equations (c)Solve a pair of linear equations (d)Solve a pair of linear equations by elimination
Introduction Lets have a look at a relatively straight single equation This is a linear equation because there are no terms involving or Suppose we choose a value of
x0123 x
Suppose we take a second formula x0123 x
When we solve simultaneous equations we are looking for the intersection of the two straight lines because this is the point that satisfies both equations at the same time. When this occurs at the point
Solve a pair of linear equations by elimination Take the two previous linear equations EQ EQ2 We need to make the x or y coefficients the same so that we can eliminate either x or y If we multiply EQ 1 by -2 we would get EQ3
To solve the equation we need to take EQ2 away from EQ EQ EQ2 Substitute x=2 into one of the equations
Comparison between graphical and elimination Graphical Elimination
Simultaneous Linear Equations Worked examples
Solve the following pairs of simultaneous equations by graphical method (a) (b)
(a) x01234 x01234
(b) x01234 x01234
Solve the following pairs of simultaneous equations by elimination method (a) (b)