Question:
Evaluate the expression 5^x - 3^x for x=2
Answer:
5^x - 3^x for x=2 is 16
Explanation:
Given
5^x - 3^x
x=2
Required
Evaluate
When fazed with question like this all you need is to substitute the value of x (or any other variable{s} used) in the expression.
Recall that x = 2
So, you have to substitute 2 for x in 5^x - 3^x
This gives

This can be further solved in 2 ways
1. Solve directly

=

= 16
2. Expand using difference of two squares.
Difference of two squares is represented by

By comparison
becomes




For both ways, we'll arrive at the same answer.
Hence, 5^x - 3^x for x=2 is 16