Year 9 Interactive Maths - Second Edition

Equations Involving Two or More Operations

To solve a linear equation, we do the same operation(s) to both sides of the equation to collect numerical terms on the right side and pronumeral terms on the left side.

Example 9

Solution:

Recommended Setting Out:

Equations in which x Appears Twice

Example 10

Solution:

Recommended Setting Out:

Problem Solving

Example 11

If three times a number, when diminished by 4, equals 17, what is the number?

Solution:

Let x be the number.
Three times x is 3x, and diminishing this by 4 gives 3x – 4, which we are told equals 17.

So, the number is 7.

Example 12

If 5 less than twice a number is 4 more than the number, what is the number?

Solution:

Let x be the number.
Five less than twice x is 2x , and 4 more than x is x

So, the number is 9.