The key phrase is ... more than ... This indicates that we should add.
... + ...
The two terms that we are adding together are 6 and the product of -3 and a certain number. Since 6 comes first in the verbal expression, it should be on the right-hand side of the addition. When we say a certain number, this is indicating an arbitrary number or a variable. If we call this number x, we can now write the full expression.
6 more than the product of -3 anda certain number
-3 x + 6
This corresponds with answer D. Note that this is only one of multiple ways to algebraically express the given verbal expression.
