# Evaluate an algebraic example

You evaluate an algebraic expression when you try to find the value of the algebraic expression by substituting a given number for each variable.

Then you can simplify the resulting numerical expression using the order of operations.

## Examples showing how to evaluate an algebraic expression.

**Example #1**

Evaluate 2a - 2^{5} ÷ b for a = 6 and b = 8

Substitute 6 for a and 8 for b

2a - 2^{5} ÷ b = 2 x 6 - 2^{5} ÷ 8

Simplify the power

2a - 2^{5} ÷ b = 2 x 6 - 32 ÷ 8

Multiply and divide from left to right

2a - 2^{5} ÷ b = 12 - 4

Subtract

2a - 2^{5} ÷ b = 8

**Example #2**

Evaluate a^{2} - 2b + c for a = 4, b = 6 and c = 3

Substitute 4 for a, 6 for b, and 3 for c

a^{2} - 2b + c = 4^{2} - 2 x 6 + 3

Simplify the power

a^{2} - 2b + c = 16 - 2 x 6 + 3

Perform the multiplication

a^{2} - 2b + c = 16 - 12 + 3

Add and subtract from left to right

a^{2} - 2b + c = 4 + 3

a^{2} - 2b + c = 7

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