Thank you Sir Denis... How did you solve it sir... please can you show the solution sir?
=53... it isnot 242....
You have posted here many many times. Are you too lazy to use available web-based calculators.?
I suspect the OP is frustrated because his follow up question is not understood. He wants to know analytically how Denis found that a solution lies between 1 and 2.
There is no mechanical trick. Even if Denis did not graph the function, he undoubtedly observed that for non-negative values of x
$f(x) = 5x^7 + + 3x^4$ increases rapidly and monotonically from a value of zero at x = 0.
It is also obvious by inspection that f(1) = 8 and f(3) >> 400. So if there is an integer solution, it must be 2. But f(2) is too large.
Thus, there is a positive solution between 1 and 2.