An equation of the shape: ax +
b = 0, where a and b – the known numbers, x – an unknown
value, is called a linear equation in one unknown. To solve this
equation means to find the numerical value of x ,
at which this equation becomes an identity.
If a is not equal to zero ( a ≠ 0
), then a solution ( root ) has the shape:
If a = 0 , then
cases are possible:
1. b = 0, then 0 · x + 0 = 0 . Here x can be any
number ( check this ! ).
2. b ≠ 0, then 0 · x + b = 0 . There is no solution ( check this also ).
expressions: x2 + 2x = x2 – 2x
+ x – 2 . Transfer all terms to the
side of the equation. After reducing all similar terms we’ll
3x + 2 = 0, hence x = – 2 / 3 .