(1.7 * 10^4) ( 5 * 10^-5)

= 0.85

To multiply two numbers in scientific notation, you need to multiply the coefficients and add the exponents.

Step 1: Multiply the coefficients:
1.7 * 5 = 8.5

Step 2: Add the exponents:
10^4 * 10^-5 = 10^(4-5) = 10^-1

Putting it all together, we get:
(1.7 * 10^4) * (5 * 10^-5) = 8.5 * 10^-1