Expert: Scott A Wilson - 10/21/2009

Question
Hi my math teacher makes us write journals about what we learn and this week he said to write about what is the difference between equations and inequalities.

Answer
An equation is where the expressions on the left side of the equal sign
are the same as the expressions on the right side.
When both sides are multiplied by a constant, whether positive or negative,
the equality is still an equality.

An inequaltiy is where the expression on one side is > the expression on the other.
(or it could be defined as where one side is < the other).
When both sides are multiplied by a negative, the sign is reversed.
Ex: 3 < 5, so -3 > -5.  Just think about that time there is an x < y: -x > y.

Same: Both sides can be multiplied by the same constant.

Difference: In the inequality, if the sign of the constant is negative,
the direction in the middle is swapped.
It is still an equals sign if it was already an equals.