Whenever we have a problem to solve we assume the unknown quantity(or value to be identified) as x. This is just a convention followed in algebra by using a variable to denote the unknown quantity and then arrive at the solution.
The value of x is a constant number .The letter "x" is often used in algebra to mean a value that is not yet known. It is called a "variable" or sometimes an "unknown".so no one can decide the fix value of x because it ia a variable .
2x=7+x than x=7
What is the value of x? (1) x^(1/2) = x - 2 (2) x ≠ 1.
From statement I alone, √x=x-2.
Squaring both sides, we have x = (x−2)2(x−2)2. Opening up the RHS and simplifying, we have,
x2x2 – 5x + 4 = 0, which can be factorized as (x-4) (x-1) = 0. Therefore, x has two values, 1 and 4. We need a unique value of x. Statement I alone is insufficient.
Answer options can be B, C or E. Answer options A and D can be eliminated.
From statement II alone, x≠1. This is not sufficient to find the value of x.
Answer option B can be eliminated.
Combining statements I and II, we have the following:
From statement I, x = 1 or 4. From statement II, x≠1.
This means, x = 4. The combination of statements is sufficient. Answer option E can be eliminated.
The correct answer option is C.