First degree equation

An equation is called a first degree equation (or linear equation), if the linear equation can be written or rewritten to the format of ax+b=0.

Examples of first degree equations:

2 × x -4 = 0
x + 5 = 8 - 2 × x
5 × (x + 2) = 4 · x

Solving first degree equations

In order to solve a first degree equation, one must isolate the unknown variable (here, called x). The sign <=> is used for telling the next equation has the same solution as the line before.

Rules for solving the equations

- You are allowed to add the same number on both sides.
- You are allowed to subtract the same number on both sides.
- You are allowed to multiply with the same number on both sides (except 0)
- You are allowed to divide with the same number on both sides (except 0)

Examples of solving first degree equations

2x - 4 = 0 <=> 2x - 4 + 4 = 0 + 4 <=> 2x = 4 x=2

0.5x + 2 = 4 <=>
2*0.5x + 2*2 = 2*4 <=> We multiply with two, on both sides.
1*x + 4 = 8 <=> Since 1x is the same as x, we can remove 1.
x + 4 = 8 <=>
x=8-4 <=>
x=4