Yes, I see. But in this equation x is not a rational number. And if in my equation: sqrt(7) - sqrt(x) , x is a rational number? Then can the result be somehow rational (and not 0)?
Yes, I see. But in this equation x is not a rational number. And if in my equation: sqrt(7) - sqrt(x) , x is a rational number? Then can the result be somehow rational (and not 0)?
You do understand this wastes people's time, if you don't specify the question clearly and we end up answering the wrong question?
Let
With a little more work we see that the only way to make x rational is to let a = 0.