Algebraic Expressions and Substitution

Front

What is an algebraic expression?

Back

An algebraic expression is a mathematical phrase that can include numbers, variables, and operation symbols. For example, 3x + 5 is an algebraic expression.

Front

What does it mean to substitute a value in an expression?

Back

Substituting a value means replacing a variable in an expression with a specific number. For example, in the expression 2x + 3, if x = 4, then it becomes 2(4) + 3.

Front

Evaluate the expression: -g - h, given g = 6 and h = -2.

Back

-g - h = -6 - (-2) = -6 + 2 = -4.

Front

Evaluate the expression: -5x + 3y, given x = 8 and y = -2.

Back

-5(8) + 3(-2) = -40 - 6 = -46.

Front

Evaluate the expression: xy + z, given x = 5, y = 3, and z = -12.

Back

xy + z = (5)(3) + (-12) = 15 - 12 = 3.

Front

Identify the variable in the expression: -7y - 7.

Back

The variable in the expression is y.

Front

Evaluate the expression: -5x + 22, given x = 9.

Back

-5(9) + 22 = -45 + 22 = -23.

Front

What is a variable in algebra?

Back

A variable is a symbol, usually a letter, that represents an unknown value in an expression or equation. For example, in the expression 2x + 3, x is the variable.

Front

What is the difference between a constant and a variable?

Back

A constant is a fixed value that does not change, while a variable can represent different values. For example, in the expression 4x + 5, 5 is a constant and x is a variable.

Front

What is the coefficient in the expression 3x + 4?

Back

The coefficient is the number that is multiplied by the variable. In this case, the coefficient of x is 3.