a numerical expression consists of numbers and operations 3+5
a variable is a letter used to represent one or more numbers. x=6
a variable expression consists of numbers, variables, and operations 7+3+4x
Evaluate a variable expression
to evaluate a variable expression, substitute a number for each variable and evaluate the resulting numerical expression
a verbal model describes a problem using words as labels and using math symbols to relate the words
Associative property of addition
(3 +2) 4 = 3+ (2 +4)
Identity property of addition
0 + b = b
Identity property of multiplication
1(-7) = -7
commutative property of multiplication
Equivalent numerical expressions
numerical expressions that have the same value
equivalent variable expressions
equivalent variable expressions have the same value for all values of the variable(s)
Terms of an expression
The parts of an expression that are added together are called terms 4y, -6. 3y
like terms are terms that have identical variable parts 4y and 3y
Coefficient of terms
The coefficient of a term with a variable is the number parts of the term 4, 3
A constant term has a number but no variable -6
an equation is a mathematical sentence formed by placing an equal sign, = between two expressions x +3 = 7
Solution of an equation
a solution of an equation with a variable is a number that produces a true statement when it is substituted for the variable. x + 2 = 4
2+2 = 4
Solving an equation
finding all solutions of an equation is called solving the equation
Inverse operations are two operations that undo each other, such as addition and subtraction
Equivalent equations are equations that have the same solutions(s)
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