Question

What is the value of x in the equation x^3 + 28 = 128?

A) 2
B) 3
C) 4
D) 5

Answer 1

To find the value of x in the equation x^3 + 28 = 128, subtract 28 from both sides and take the cube root. The closest whole number cube greater than 100 is 125, which is 5 cubed. The answer is D) 5.

Step-by-step explanation:

The value of x in the equation x3 + 28 = 128 can be found by first simplifying the equation to isolate x. Here are the steps we'll follow:

1. Subtract 28 from both sides of the equation to get x3 = 100.
2. Take the cube root of both sides to solve for x. The cube root of 100 is not a whole number, but we can assess the given options to find the closest whole number cube root.
3. Since 43 equals 64 and 53 equals 125, the value of x must be between 4 and 5. Looking at the options given, the only value that makes sense is 5 because it's the only number whose cube is greater than 100.

Therefore, the correct answer is D) 5.