1. Why is algebra needed?
Many everyday problems are solved by people in their heads. They are actually using algebra without even knowing it!
When the problems get more difficult, the problems and their answers need to be written down. Algebra provides a way to do this.
2. Why are x and y used so much in algebra?
When people first started using algebra these were the letters frequently used. It may have been because using a would have been confusing with a being a word on its own.
x and y are near the end of the alphabet and are not often used for other things.
In a graph, x and y are often used to label the horizontal and vertical axes.
In a function y is often used as the subject of the equation and x is often used as the variable in the equation.
Any other letter from a to z or letters such as those from the Greek alphabet are also often used for variables in algebra.
3. In algebra, is x + 2 the same as 2 + x?
Yes, they are the same. Operations in algebra obey all of the rules that are used with arithmetic.
So although x + 2 = 2 + x is true,
it is not true that x − 2 = 2 − x.BEDMAS applies to all operations in algebra.
