Evaluating Expressions

The difference of squares formula states that a² - b² = (a - b)(a + b).

To evaluate an expression, substitute the given values for the variables into the expression and perform the arithmetic operations according to the order of operations.

The order of operations is Parentheses, Exponents, Multiplication and Division (from left to right), Addition and Subtraction (from left to right), often abbreviated as PEMDAS.

Substituting the values gives 5(-7) + 9(4) = -35 + 36 = 1.

To evaluate a rational expression, substitute the values for the variables and simplify the fraction if possible.

Substituting the values gives (12(3)(-1))/(3 - (-1)) = (-36)/(4) = -9.

Negative numbers can affect the outcome of expressions, especially in multiplication and addition, where they can change the sign of the result.

Substituting the values gives 10(-6) - (-6)(2) + (2)³ = -60 + 12 + 8 = -40.

A polynomial expression is a mathematical expression that consists of variables raised to whole number powers and coefficients, combined using addition, subtraction, and multiplication.

Substituting the values gives 4² - (-2)² = 16 - 4 = 12.