So you have x^3 - 4x = 0. What you can do is pull out an x from both x^3 and - 4x so it looks like this:
Then you can find a number that makes the part inside the parentheses turn into zero. For beginners, it may be easier to write it out seperately and solve for x.
We need to solve for x, so the first step is to add 4 to both sides, so we get something like this:
Then, we can square root both sides to get rid of the power on the x, so it looks like this:
Now, every square root has two answers, a positive and a negative. If we look at the bottom example:
We can see that both -2 and 2 to the power of two will equal to 4.
So finally, we get:
These are the other 'Zero's for the original function. If you are not sure of what a 'Zero' is, it is where the function crosses over the x-axis on a graph.
Answer:
30
Step-by-step explanation:
Using a system of equations, it is found that Gina got 22 questions correct in the test.
<h3>What is a system of equations?</h3>
A system of equations is when two or more variables are related, and equations are built to find the values of each variable.
In this problem, the variables are:
- Variable x: Number of questions she got correct.
- Variable y: Number of questions she got wrong.
The test has 30 questions, hence:
x + y = 30 -> y = 30 - x.
She scored 152 points, hence, considering the value of each question:
8x - 3y = 152.
Since y = 30 - x:
8x - 3(30 - x) = 152
11x = 242
x = 242/11
x = 22
Gina got 22 questions correct in the test.
More can be learned about a system of equations at brainly.com/question/24342899
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