Final answer:
The expression (10c⁶ d⁻⁵) (2c⁻⁵ d⁴) is equivalent to (20c⁶ d⁻¹). Therefore, the correct equivalent expression is (20c⁶d⁻¹) (option b).
Step-by-step explanation:
The expression (10c⁶ d⁻⁵) (2c⁻⁵ d⁴) can be simplified using the rules of exponents.
When multiplying exponential expressions with the same base, you add the exponents.
In this case, the 'c' terms have exponents of 6 and -5, and the 'd' terms have exponents of -5 and 4.
So, the simplified expression is:
(10c⁶ d⁻⁵) (2c⁻⁵ d⁴) = (10 * 2) c⁶⁺⁻⁵ d⁻⁵⁺⁴ = 20c d⁻¹ = (20c⁶d⁻¹)
Therefore, the correct equivalent expression is (20c⁶d⁻¹) (option b).