Need help with this problem

[abel muroi]

let x > 1, the expression SquareRoot(7x⁴ - 7x²) is equivalent to


A. SquareRoot(7x)

B. SquareRoot(7x²) - SquareRoot(7x)

C. 7(SquareRoot(x⁴ - x²))

D. SquareRoot(7x) (x² - 1)^1/2

I believe that C is the correct answer since all i need to do is multiply the 7 with x⁴ and x² to get the original expression

Am I wrong?

 

[Ishuda]

let x > 1, the expression SquareRoot(7x⁴ - 7x²) is equivalent to


A. SquareRoot(7x)

B. SquareRoot(7x²) - SquareRoot(7x)

C. 7(SquareRoot(x⁴ - x²))

D. SquareRoot(7x) (x² - 1)^1/2

I believe that C is the correct answer since all i need to do is multiply the 7 with x⁴ and x² to get the original expression

Am I wrong?

As it stands, none of the choices are correct. However, if you were to change C. to
C. SquareRoot(7) SquareRoot(x⁴ - x²)
I would agree that the answer was C

 

[Deleted member 4993]

let x > 1, the expression SquareRoot(7x⁴ - 7x²) is equivalent to


A. SquareRoot(7x)

B. SquareRoot(7x²) - SquareRoot(7x)

C. 7(SquareRoot(x⁴ - x²))

D. SquareRoot(7x) (x² - 1)^1/2

I believe that C is the correct answer since all i need to do is multiply the 7 with x⁴ and x² to get the original expression

Am I wrong?

Or change D to:


D. SquareRoot(7) * (x) * (x² - 1)^1/2

 

[Ishuda]

Or change D to:


D. SquareRoot(7) * (x) * (x² - 1)^1/2

Maybe it should be
D. SquareRoot(7) * |x| * (x² - 1)^1/2

 

[lookagain]

Maybe it should be
D. SquareRoot(7) * |x| * (x² - 1)^1/2

In that hypothetical problem, the absolute value bars would not be needed,
because of the condition given that n > 1.

 

[Ishuda]

In that hypothetical problem, the absolute value bars would not be needed,
because of the condition given that n > 1.

Right - I didn't look at that again. Just shows I should pay more attention in some cases. [I assume you meant x and not n though]