Number of solutions to $1/x+1/y=1/1995$ in $N\times N$
10753
Natural number solutions to $\frac{xy}{x+y}=n$ (equivalent to $\frac 1x+\frac 1y=\frac 1n$)
29876
Find the number of triples $(x,y,z)$ of real numbers satisfying the equation $x^4+y^4+z^4+1=4xyz$
108885
Systems of equations with a single number
99264
the number of positive-integer solutions that satisfy $x_1\cdot x_2\cdot x_3\cdot x_4=1,000,000$?
126820
How many positive integer solutions are there to the equality $x_1+x_2+...+x_r= n$?
60902
Find general solution for the equation $1 + 2 + \cdots + (n − 1) = (n + 1) + (n + 2) + \cdots + (n + r) $
144863
Finding integer solutions to $y^2=x^3-2$
10926
System of Linear Equations - how many solutions?
94407
Number of solutions for $x[1] + x[2] + \ldots + x[n] =k$
1001
Number of integer solutions of $x^2 + y^2 = k$
123159
Solutions of the diophantine equation $x+y+z=xyz$?
115244
Integer solutions of $m^2+(m+1)^2=n^4+(n+1)^4$
69791
How to solve: T(n) = T(n - 1) + n
114228
Find the number of solutions to $ \lfloor x \rfloor + \lfloor 2x \rfloor + \lfloor 4x \rfloor + \ldots + \lfloor 32x \rfloor =12345$
35066
Nature and number of solutions to $xy=x+y$
44354
Total number of solutions of an equation
153170
Find the number of solutions of the equation $e^{4x}+e^{3x}-4e^{2x}+e^x+1=0$