Question

X=-1/4
Value of x is ______

Answer 1

So, doing a quick ballpark estimate of what we’re after here, we want some number raised to the fourth power, plus the fourth ROOT of that same number, to equal 18. If we evaluate the variable expression with 1, we get an answer of two. (One to the fourth power is one, and the fourth root of one is one. One plus one is two. I’m going to ignore the fact that -1 is also a fourth root of one because it doesn’t matter here.)

If we evaluate the variable expression with 2, we get that 16 + 2^(1/4) = approximately 17.2, which is awfully close to 18. Using 3 causes us to way overshoot, so we know we’re looking for something really close to 2.

Solve it like this:

Rearrange:

x^(1/4) = 18 - x^4

Now raise both sides to the fourth power:

x = (18-x^4)^4

Expand the right side and get:

x=104976-23328x^4+1944x^8-72x^(12)+x^(16) (Thanks Symbolab)

Solving this, which I also left up to Symbolab, gets you one real solution:

x= approximately 2.02476

:(

#leaving soon

Answer 2

Answer:

The value of x is already given in the question which is -1/4

Common sense bro!