This lesson is an introduction to algebra

# How to solve a simple algebra equation

Solving an equation is finding a missing value in the equation. For example you could be asked: solve 2 + x = 4 or Find the value of X in the equation.

**What does x mean? **X simply means an unknown value, we can use any alphabetical letter we want to represent this missing value, it’s also called (variable).

In the above equation (2 + x = 4) we have to find the value of X. In other words, find a number that we add to 2 and get 4. You probably guessed the answer which is 2 (2 + 2 = 4). When we replaced the X by 2 we checked whether the equation makes sense or not (is 2 + 2 equals 4) and the answer is yes.

So far, we solved equations by guessing, that works for simple equations. However, for more complex equations we need to use **Solving by inverse operation.**

Take a look at the following equation: **2x + 4 = 20**

(!) **2x simply means (2 ****times x) however, we don’t write the times sign in algebra equation so when you see a number with a letter besides each other, they are by default times each other.**

How would you solve an equation like this? Let’s break that down.

(2x + 4 = 20) Wouldn’t it be easier if we get rid of the 4? we can easily do that by subtracting 4 from both sides as if we subtract 4 from 4 we have 0.

So 2x + 4 **– 4** = 20 **– 4**

After subtracting: 2x = 16

Now we need to get rid of the 2 and have the x alone on its side. So we can divide both sides by 2 (opposite of multiplication is division)

So 2x ÷ 2 = 16 ÷ 2

After dividing x = 8

And we have the result x is equal to 8.

**Let’s sum that up**

2x + 4 = 20

2x + 4 – 4 = 20 – 4

2x = 16

2x ÷ 2 = 16 ÷ 2

x = 8