RecapUsing the

substitution method, solve the simultaneous equations:

4.4 Simultaneous Equations by ‘Elimination’.

ESSENTIAL QUESTIONHow to solve a system of equations

simultaneously via elimination?

TheorySolving 2 (or more)equations simultaneously means finding x and y values that makes both equations true.

Example: and .(both have same variables and same solutions)

In the elimination method, one equation is added or subtracted with the other to eliminate one variable and the resulting equation is solved for the remaining variable.

Then, using the worked out value and one of the equations, the other variable is solved.

(the 2 solutions should make both equations true)

Example 1Solve these equations

simultaneously using the elimination method:

(Which one either x or y can we get rid off?

Should we add or subtract the two equations?)

Solution:

Example 2Solve these equations

simultaneously using the elimination method:

2

Example 3Using elimination method, solve

these equations simultaneously:6

Work SetEx: 4.4, Text Numbers 1, 2, 4, 5 (LHS only).

ALGEBRA TEST – Thursday 19/3/1545 mins, full working required, Do Chapter Review questions for prep.