Math and Arithmetic

Algebra

Calculus

# Evaluate the variable expression for x equals 3?

###### Wiki User

###### December 16, 2009 5:29PM

Take 3 and substitute into the expression given to you but not mentioned in the question here and evaluate the expression. "Sub and Solve" I say.

## Related Questions

###### Asked in Math and Arithmetic, Algebra, Calculus

### What is the expression for x equals 3 and y equals 6?

A mathematical expression in its' most simplistic form, merely
assigns a value to a variable. Don't confuse an expression with an
equation. An equation requires a solution. An expression cannot be
"solved". It only allows you to determine the value of a
variable.
This is the expression in words "x is equal to 3" (X is the
variable which is equal to the constant number 3)
This is the expression in numbers "x=3"
The expression in words "y is equal to 6" (Y is the variable
which is equal to the constant number 6)
The expression in numbers is "y=6"
I hope you understand now.

###### Asked in Algebra

### What do you call replacing a variable in an expression by a number?

A variable is a letter that represents a number. An
expression that contains at least one variable is called
variable expression, also called algebraic
expression. A variable expression has one or more terms. A
term is a number, a variable, or a product of numbers and
variables. For example,
3(x^2)y + 2xy + x - 7 is a variable expression, where you have 4
terms.
When working with variable expression, you often use the
substitution principle:
If a = b, then a may be replaced by b in any
expression.
The set of numbers that a variable may be represent is called
replacement set, or domain, of the variable. To
evaluate a variable expression, you replace each variable with
one of its values and simplify the numerical expression that
results.
Example: Evaluate the expression 2x - 4y for x = 5 and y =
-9.
Solution:
2x - 4y
= 2(5) - 4(-9)
= 10 + 36
=46