Algebra

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In algebra, we use addition, subtraction, multiplication, division, and exponents to find the values of variables in an equation. In algebra, we also use letters (a,b,c,...A,B,C) to stand for numbers.

For example, let's say we want to find x in this equation: x - 5 = 2

If we use algebra, we could add five to both sides (x - 5 + 5 = 2 + 5, x = 7) to find out that x equals 7.

Since the rules of algebra work in real life and we can use numbers to represent the values of real things, we can use algebra to solve real problems.

For example, if I give 5 coins to a friend and have 10 left over, how many did I have before? We are trying to find out how many I had before, so we will call that x. How many coins I had before minus how many I gave to my friend equals how many coins I have now, so x - 5 = 10. We can add five to each side to find that x - 5 + 5= 10 + 5, x = 15. X, the number I had before, equals 15. I had 15 before.

In Algebra, adding z to y (or y plus z) is written as y + z.

In Algebra, subtracting z from y (or y minus z) is written as y - z.

In Algebra, multiplying y by z (or y times z) can be written in 3 ways: y x z, y*z or yz. yz is the most usual form of writting the product of y and z in Algebra

When we multiply a number and a letter in Algebra, we write the number in front of the letter. When the number is 1, then 1 is not written.

In Algebra, dividing y by z is written as y */* z or y/z. y/z is more commonly used.

The word 'Algebra' comes from a Mathematics book written by a famous Arabian mathematician. He wrote that book in the 9th century. The book was brought into Europe and translatedd into Latin in the 12th century. The book was then given the name 'Algebra'.

See

List of mathematics topics