Answer:
A
Step-by-step explanation:
So we have the equation:

First, let's subtract 16 from both sides:

Now, let's divide both sides by 3:

Remember that with fractional exponents, we can move the denominator into the root position. Therefore:
![(\sqrt[3]{x-4})^4=16](https://tex.z-dn.net/?f=%28%5Csqrt%5B3%5D%7Bx-4%7D%29%5E4%3D16)
Let's take the fourth root of both sides. Since we're taking an even root, make sure to have the plus-minus symbol!
![\sqrt[3]{x-4} =\pm 2](https://tex.z-dn.net/?f=%5Csqrt%5B3%5D%7Bx-4%7D%20%3D%5Cpm%202)
Cube both sides. Since we're cubing, the plus-minus stays.

Add 4 to both sides.

Calculator:

So, our answer is A.
And we're done!
Answer:
33.3333% decrease
Step-by-step explanation:
Percent change formula:
, where x is the new value and y is the starting value.
Plug in values and solve:

-33.3333% change, or a 33.3333% decrease.
25% 6 divided by 24 will give you the percentage of copper in the bar
X^4 + x^3 + x^2 + x = 0
x(x^3 + x^2 + x + 1) = 0
x[x^2(x + 1) + 1(x + 1)] = 0
x(x + 1)(x^2 + 1) = 0 ⇔ x = 0 or x + 1 = 0 or x^2 + 1 = 0
x = 0 or x = -1 or x^2 = -1 -false
Answer: x= 0 or x = -1.