Given that x + 1 / X is equal to 7 under the root sign, find the value of 2x

Given that x + 1 / X is equal to 7 under the root sign, find the value of 2x

A:
x+1/x=√7
x^2-√7x+1=0
(x-√7/2)^2=-1+7/4
(x-√7/2)=3/4
X - √ 7 / 2 = √ 3 / 2 or X - √ 7 / 2 = - √ 3 / 2
So:
X = (√ 7 + √ 3) / 2 or x = (√ 7 - √ 3) / 2
So:
2X = √ 7 + √ 3 or 2x = √ 7 - √ 3

What's the root of three times, 7-1 of 8? It's going to leave in 20 minutes

=Third root (- 1 / 8)
=-One in two

Can anyone tell me why the third power of root 49 equals one of the third power of root 7

(root 49) ^ 3 / 7 = [root (49 / 7x7x7)] ^ 3 = (root 1 / 7) ^ 3 = 1 / (root 7) ^ 3
See?

For any number a, does the square root of a be equal to a?

There are answers in the textbook. Conclusion: not necessarily. It should be √ A / = | a|
For example: √ 5? = √ 25 = 5;
(5 is the opposite of - 5!)
The reason is simple: the formula √ a can only represent the arithmetic square root of a (not the negative square root)

The square of root a is equal to a The square of root a is equal to a, and the square of a divided by a is equal to a Isn't that right? It should be a greater than or equal to zero, right? It should be the square of a under the root

EN

For any number a, does the square of the root a be equal to a?

No, only if a > = 0 is equal to a when a is a

For any number a, must the square of the root a be equal to a?

Not necessarily. When a is greater than or equal to zero, the square of root a is equal to A. when a is less than zero, the square of root a is equal to - A

If the square of the root a is equal to 2, then a is equal to

a=2 ,-2

High score 100: 3 √ (a) · 6 √ (- a) is equal to what? Please write the steps clearly (a under three times of root sign times - A under six times root sign) This is how I calculate the formula = (the third power of a) times (- A's sixth power) = - (root a) The answer is not

Obviously, to make the sixth power of - a meaningful, you have to - a > = 0, that is, a = 0
So 3 √ (a) · 6 √ (- a) = - 1 × (- a) to the third power of × (- a) = - √ (- a)

What is 48 times 75 under the radical,

√（48×75）
=√3×16×3×25
=√3²×4²×5²
=√（3×4×5）²
=3×4×5
=60