16 (sqrt (x-3) ) (sqrt (x-1))

What is the question? All you have written is an algebraic expression.

i have to multiply them

To multiply the given expression, 16√(x-3) * √(x-1), we can follow these steps:

Step 1: Simplify the expression.
We'll start by multiplying the numbers outside the square roots:
16 * 1 = 16

Next, we'll combine the square roots with the same radicand (the expression inside the square root sign):
√(x-3) * √(x-1) = √((x-3) * (x-1))

Step 2: Multiply the expressions inside the square root sign.
To multiply (x-3) and (x-1), we'll use the distributive property:
(x-3) * (x-1) = x^2 - x - 3x + 3

Step 3: Simplify the expression inside the square root sign.
Combining like terms, we have:
x^2 - 4x + 3

Step 4: Put everything together.
Putting it all together, we have:
16 * √(x^2 - 4x + 3)

Therefore, the simplified expression after multiplying is:
16√(x^2 - 4x + 3)

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