Using mathematical operations
An operation is a mathematical process. Common examples are addition (+), subtraction (-), multiplication (x) or division (梅).
An inverse operation is the opposite of the operation used in the equation.
+ is the opposite of -
- is the opposite of +
x is the opposite of 梅
梅 is the opposite of x
Writing an equation
Let's turn the problem below into an equation.
3 loaves of bread and a 拢4 pack of cheese cost 拢10. How much is each loaf?
In this equation we want to work out the cost of one loaf of bread.
As the cost of bread is the unknown, we will represent this with an x.
We need 3 loaves of bread, so in our equation we will represent this with 3x.
We know the cheese costs 拢4 and the total spend is 拢10.
So now we can write our equation:
3x + 4 = 10
Solving an equation
When solving an equation it is important to find the value of one letter.
Let's solve the equation 3x + 4 = 10.
3x + 4 = 10
- To remove the + 4 we complete the inverse (opposite) operation by subtracting the 4.
3x + 4 - 4 = 10 鈥 4
3x = 6 (3 loaves cost 拢6)
- To work out the cost of one loaf we divide both sides of the equation by 3.
x = 6 梅 3
So x = 2 (one loaf costs 拢2)