. The expression (a2b3)(a−2b−3)=?

The expression (a^2b^3)(a^-2b^-3) simplifies as follows:

Step 1: Apply the product rule of exponents, which states that when you multiply two powers with the same base, you add the exponents. In this case, however, the exponents are negative for the second set of terms, so you're effectively subtracting them:

a^(2-2) * b^(3-3)

Step 2: Simplify the exponents:

a^0 * b^0

Step 3: Any number (except zero) raised to the power of 0 is 1. Therefore:

1 * 1 = 1

So, (a^2b^3)(a^-2b^-3) = 1.