Year 10 Interactive Maths - Second Edition

Solving Equations

E.g. x + 5 = 9 is an equation of the first degree, which is often called a linear equation.

Many problems can be solved by using linear equations.

Recall that:

Equations behave like a balance. So we need to apply the same operation to both sides of an equation to maintain the balance. This means we can:

• add the same number to both sides of an equation
• subtract the same number from both sides of an equation
• multiply both sides of an equation by the same number
• divide both sides of an equation by the same number

Equations Involving One Operation

Example 1

Solution:

Note:

We can check the solution as follows:

So, our solution, x = 5, is correct.

Example 2

Solution:

Check:

So, our solution, x = 10, is correct.

Example 3

Solution:

Check:

So, our solution, x = 3, is correct.

Example 4

Solution:

Check:

So, our solution, x = 15, is correct.

Key Terms

linear equations, first degree equations, operation