Chapter 3- Inequalities and simultaneous equations (Pure Maths)

Question 1

how to change the direction of a inequality?

Answer 1

multiplying or dividing by negative numbers changes the direction of the inequality sign.

Question 2

How to write in interval notation? e.g 1< x ≤2

Answer 2

( round bracket means its not included
[ means number is included (it has more room)

1< x ≤2
is
(1,2]

Question 3

how to write set notation? e.g x ≤ 2

Answer 3

x ≤2

{x:x≤2}

Question 4

How to graph inequalities?

Answer 4

1. Write each inequalities as an equation
2. draw graph for each equation
3. work out which side you want
4. label correct region

Question 5

how to solve simultaneous equations where they’re both linear?

Answer 5

1. Match coefficients
   2) Eliminate to find one variable
   3) Find the other variable (that you eliminated )
   4) check your answer

Question 6

how to solve simultaneous equations if one is not linear?

Answer 6

1) isolate variable in linear equation
2) substitute into the quadratic equation
3) solve to get values for one variable
4) put these values in the linear equation