1.9 Simultaneous Equations and Inequalities

Question 1

What are the 3 methods of solving simultaneous equations?

Answer 1

1. Elimination
   (8h + 3d = 120)
   (4h + 3d = 36) =
   (4h + 0d = 84)
2. Substitution
3. Intersection of the graphs of the equation.

Question 2

When you multiply or divide inequalities by a negative number..?

Answer 2

The inequality sign is reversed.

Question 3

How to solve a pair of simultaneous equations where one is non-linear?

Answer 3

1. Make x or y the subject of the LINEAR equation.
2. Substitute this rearranged equation for x or y in the NON-LINEAR equation.
3. Solve to find x or y.
4. Substitute back into the linear equation to find pairs of solutions.

Question 4

When solving a quadratic inequality, it is advisable to..?

Answer 4

Sketch the graph.