Evaluating Expressions

To evaluate an expression with variables, substitute the values of the variables into the expression and perform the arithmetic operations according to the order of operations (PEMDAS/BODMAS).

PEMDAS stands for Parentheses, Exponents, Multiplication and Division (from left to right), Addition and Subtraction (from left to right). It is the order of operations used to evaluate expressions.

Substitute p = 6 and r = -2 into the expression: 4(6 - (-2)) = 4(6 + 2) = 4(8) = 32.

Substituting x = 3 and z = 5 gives (3 + 5 - 5) ÷ 3 + 3 = (3) ÷ 3 + 3 = 1 + 3 = 4.

Substituting y = 5 and z = 6 gives 6^2 - (5 + 4) = 36 - 9 = 27.

Substituting y = -4 and z = -3 gives (-4 + -3)^2 = (-7)^2 = 49.

Substituting b = 4 and c = 3 gives 4(4*3 + 3) = 4(12 + 3) = 4(15) = 60.

Parentheses indicate which operations should be performed first in an expression, following the order of operations.

An expression is a combination of numbers, variables, and operations without an equality sign, while an equation states that two expressions are equal.

Exponents indicate how many times a number (the base) is multiplied by itself, and they are evaluated after parentheses but before multiplication and addition.