This doesn't seem right (problem with a question)

[jlevi.esquire]

If x is an integer and 4x < 100, what is x?

(1) 4(x + 1) - 4(x - 1) > 100
(2) 4(x + 1) + 4x > 100

In the explanation, it stipulates that X must be 1, 2, or 3... however, the question never says that X is a positive integer?

JL

[tim]

the explanation does not state that x must be 1, 2, or 3. these were just example values used to test what would happen. the solution would remain unchanged if you tested non-positive integers as well..

(for the benefit of other students, the actual question has all the x's and x+1's or x-1's as exponents, i.e. powers of 4)

[thakkar.sameer]

hi

Can you please explain this with negative integers values for x ?

Sameer

[jnelson0612]

Sameer, are you familiar with the concept that negative exponents cause you to take the reciprocal of the number and then apply the exponent? For example, 4^-2 is (1/4)^2, or 1/16. Test out some negative numbers and see if any of them are possible values for x in the statements.