If you mean x30+y51=2130 there are many answers for x and y, because this equation only shows the relationship between x and y. For example, if x=0, y=1.16215 approx, and if y=0, x=1.29106 approx. The sum x+y varies. In the examples, the sums are 1.16215 and 1.29106. When x=y, the solution is about 1.1612, so the sum is about 2.3224. Also, note that since the power of x is even, y=0, x=-1.29106 is also a solution. When x and y are both positive, y never exceeds 1.16215 and x never exceeds 1.29106.