To solve the problem of determining the exponent Marina should use for [tex]\( b \)[/tex] in the expression
[tex]\[
-\frac{1}{2} a^4 b^{\square}
\][/tex]
we need to identify which of the given options matches the necessary exponent for [tex]\( b \)[/tex]. The options provided are:
- [tex]\( -7 \)[/tex]
- [tex]\( -1 \)[/tex]
- [tex]\( 1 \)[/tex]
- [tex]\( 7 \)[/tex]
Careful analysis shows that the correct exponent value for [tex]\( b \)[/tex] should be [tex]\( -7 \)[/tex].
So, Marina should use the exponent [tex]\( -7 \)[/tex] for [tex]\( b \)[/tex] in the given expression.
Thus, the answer is [tex]\( -7 \)[/tex].
