The standard form of a polynomial is written in descending order of exponents of the variable(s), so we need to simplify each term and combine like terms.
Starting with $a^2b$, there is no simplification to be done, so it remains the same.
For $(5a)^3$, we need to cube the coefficient and the variable:
$(5a)^3 = 5^3 \cdot a^3 = 125a^3$
Finally, $6^3 = 216$, so we can substitute that into the last term.
Putting it all together, the polynomial in standard form is:
$a^2b + 125a^3 + 10 - 216$
Simplifying the constant terms, we get:
$a^2b + 125a^3 - 206$
Therefore, the polynomial in standard form is $a^2b + 125a^3 - 206$.
It’s -206.