Question

Please help me with this question, it says:

Solve the equation
x to the power of 3, take away x equals to 120
Using a trial and improvement method.
You must show working out.

Answer 1

x = 5.

Explanation:

x^3 - x = 120

We first guess the value of x and calculate the left side.

Take x = 4:-

4^3 - 4 = 64-4 = 60

This is < 120 so try x = 5:

5^3 - 5 = 125 - 5 = 120.

So one solution is x = 5.