Use Concepts of Algebra

We have looked at the command words in algebra in a different activity.

 

Let's use these along with algebraic language in this activity.

 

Recap

8n  is a term 
8n + 4  is an  expression 
8n + 4 = 20  is an  equation

 

Let's try a question!

 

Example

Gracie is x years old.

Her brother Max is 3 years older.

Write an expression for their total ages.

 

Answer

We know Gracie's age is x.

If Max is 3 years older we can write his age as x + 3 (that means Gracie's age + 3 yrs).

 

Their total ages are:

x + x + 3 which we can simplify by collecting like terms:

= 2x + 3       (this is an expression).

 

 

Part 2

If we knew that the combined ages of Gracie and Max is 25 years, we could make an equation with the expression we have: 

2x + 3 = 25       

We could then solve this to find Gracie's age (x).

2x = 22

x = 11

Therefore, Gracie is 11 years old and Max is 3 years older, so he is 11 + 3 = 14 years old.

 

Let's try some of these!