Year 8 Interactive Maths - Second Edition

Equations

It is clear that the number sentence
     5 + 10 = 15
is an equation.

If the value of the pronumeral x is 5, then x can take the place of 5; and we can write this equation as

     x + 10 = 15

This is an equation containing the pronumeral x.  The value of the pronumeral x is 5.

Example 1

Describe each of the following equations in words:

Solution:

Example 2

Write an equation to represent each of the following statements:
a.  When I add 7 to a number, the answer is 16.
b.  When I subtract 8 from a number, the answer is 23.
c.  When I multiply a number by 9, the answer is 27.
d.  When I divide a number by 5, the answer is 29.

Solution:

Remember:

An equation is a statement consisting of number(s) and pronumeral(s) that are linked together with an equal sign.

Key Terms

equation, number sentence