20% of X is Y, then X is?

Question

Please help me to find out X:

20% of X is Y, then what is X?

For Example if 20% of X is 1030, what was that X?

Please don't just give me the fish. Let me know how to catch.

Thanks

Answer 1

Okay,

$1030=\dfrac{20}{100}x-x\implies 1030=-\dfrac{4}{5}x$

$x=-\dfrac{5150}{4}$