She wrote a 4 instead of a 3.
There are only 3 numbers that are greater than 7. They are 8, 9, and 10. Mariah must have include 7 in her list. That is how she got 4 instead of 3.
x=-26 is the final anwser :)
Answer:

or

Step-by-step explanation:
The expression
can be simplified by first writing the fraction under one single radical instead of two.

5/15 simplifies because both share the same factor 5.
It becomes 
This can simplify further by breaking apart the radical.

A radical cannot be left in the denominator, so rationalize it by multiplying by √3 to numerator and denominator.

use brainly to find the answer
I hope this helps you
3.9^2-42
3.81-42
243-42
201