ANSWER
[tex]-8a^7[/tex]EXPLANATION
We want to find the product of the monomials given:
[tex]4a^2\cdot-2a^5[/tex]To do this, we will combine the terms that are alike and simplify them.
That is multiply the integers with the integers and the algebraic term with the algebraic term.
[tex]4\cdot\text{ -2 }\cdot a^2\cdot a^5[/tex]Apply the addition law of indices:
[tex]\begin{gathered} -8\cdot a^{2\text{ + 5}} \\ =>-8a^7 \end{gathered}[/tex]That is the answer.