Final answer:
To write the given expression in standard form, multiply the coefficients and add the exponents for the same variables.
Step-by-step explanation:
The given expression is -8ab(-2.5)b².
To write it in standard form, we need to simplify the expression by multiplying the coefficients, and adding exponents when multiplying the same variables.
Thus, the expression can be rewritten as -8 × (-2.5) × a × b × b² = 20ab³.