Answer:
The answer is [tex]-9a^{7}b^{4}[/tex].
Step-by-step explanation:
To simplify this problem, start by multiplying [tex]a^3[/tex] by [tex]a^4[/tex] by adding the exponents, which will look like [tex](-3a^7b)*(3b^3)[/tex]. Next, multiply [tex]b[/tex] by [tex]b^3[/tex] by adding the exponents, which will look like [tex](-3a^7b^4)*(3)[/tex]. Then, multiply 3 by -3, which will look like [tex]-9a^7b^4[/tex]. The final answer is [tex]-9a^7b^4[/tex].
