As per given by the question,
There are given that a statement,
13 less than Helena's score is 46.
Now,
Suppose h is represent the Helena's score.
Then,
13 less than the Helena's score.
That means,
Subtract 13 from the Helena's score.
So,

Now,
According to the question,
13 less than Helena's score is 46.
So,

Hence, the equation is, h-13=46.