If , which of the following best represents x when y = 4?

1
1+_ sqrt(2)
1+_2sqrt(2)
4

To determine which of the given options best represents x when y = 4, we need to substitute y = 4 into each option and simplify it. Let's go through each option one by one:

1. substitute y = 4 into the first option:
x = 1
So, when y = 4, x = 1.

2. substitute y = 4 into the second option:
x = 1 + √2
So, when y = 4, x = 1 + √2.

3. substitute y = 4 into the third option:
x = 1 + 2√2
So, when y = 4, x = 1 + 2√2.

4. substitute y = 4 into the fourth option:
x = 4
So, when y = 4, x = 4.

Now, we need to compare these values and determine which one is the best representation of x when y = 4.