algebra – the branch of mathematics where letters and symbols are used to represent numbers
(pronounced al-juh-bruh)
To remember the meaning of algebra, use the following mnemonic:
The owl just wearing a bra (algebra) had a letter saying he was the substitute for the footballer with a number on his shirt (letters are substitutes for numbers).
Instead of working with specific numbers, algebra introduces letters (like a, b, or x) that can stand for unknown values or changing quantities. This allows you to express general relationships and patterns, solve problems where some information is missing, and work with abstract mathematical concepts.
Example 1
One of the most famous algebraic expressions is:
E = mc2
The letters (energy) and (mass) are variables and the letter is the speed of light which is a constant.
Example 2
ax2 + bx + c = 0
A famous algebraic equation is the quadratic equation.
Example 3
A simple example of an algebraic equation is as follows:
3x - 7 = 2x + 11
To solve this, first subtract 2x from both sides to get x - 7 = 11, then add 7 to both sides to find that x = 18. You can verify this by substituting 18 back into the original equation: the left side gives (3 x 18) - 7 = 54 - 7 = 47, and the right side gives (2 x 18) + 11 = 36 + 11 = 47, so both sides match.
