The equation we have is:

To solve this equation we need to find a value of x for which the result is 50.
By graphing

and also

When you find the intersection between those lines, you will find the solution of the initial equation, which is what Leah is doing.
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The graphs intersect at the point (3.56, 50) in this point 3.56 represents the x-value and 50 represents the y-value, thus for 3.56 the result of the equation is 50.
Solving the statement:
In the first option ''exactly at'' is the correct choice because the intersection between the graphs is exact and not an approximation.
In the second drop-down menu, ''exactly'' is again the correct choice because the intersection is exact and not approximate.
In the third drop-down menu, remember that the equation was

And since the intersection is at (3.56, 50) this means that when the value of x is 3.56, the value of y is 50, thus the solution for the equation is exactly 3.56, for the third menu 3.56 is the correct choice.