(A+b)2

Algebra is built on expressions and equations. An expression is a combination of numbers, variables, and operation signs (like 2x + 5). An equation sets two expressions equal to each other (like 2x + 5 = 11). Your main goal in algebra is often to "solve" an equation, meaning finding the value of the variable that makes the equation true.

A variable is a symbol, typically a letter (like x, y, a), that represents an unknown number. It's a placeholder.

Multiplying two binomials means taking an expression like (a + b) and multiplying it by another expression like (c + d). The result will be an expression with four terms, which you'll then simplify if possible.

• First: Multiply the first terms in each binomial.
• Outer: Multiply the outermost terms in the entire expression.
• Inner: Multiply the innermost terms in the entire expression.
• Last: Multiply the last terms in each binomial.

In algebra, an expression is a combination of numbers, variables, and operation signs. A polynomial is a special type of algebraic expression. What makes a polynomial special? It can only have terms where variables are raised to non-negative integer powers (like $x^2$, $y^3$, $z^0$ which is just 1) and there are no variables in the denominator or under square roots.