Assuming X and x are referring to the same variable.
Assuming Y and y are referring to the same variable.
The system of linear equations has exactly one solution.
The substitutions are x=691, y=61.
XY=3691
Solve 7x+5y=107 for x. x=7107−75y
Substitute 7107−75y for x in 5x+7y=77 and simplify. 5x+7y5(7107−75y)+7yy=77=77=61
Use substitution of the numerical value of y to get the values of x. xxx=7107−75y=−6⋅71⋅5+7107=691
By substituting these values into the expression, we find that:XY=691⋅61=3691