Questions: Find the real solutions of the equation.
7 x^(2 / 3) - 48 x^(1 / 3) - 7 = 0
What is the solution set? Select the correct choice below and fill in any answer boxes within
A.
(Use a comma to separate answers as needed. Type an integer or a simplified fraction)
B. There are no solutions.
Transcript text: Find the real solutions of the equation.
\[
7 x^{2 / 3}-48 x^{1 / 3}-7=0
\]
What is the solution set? Select the correct choice below and fill in any answer boxes within
A. \{ $\square$ \}
(Use a comma to separate answers as needed. Type an integer or a simplified frac
B. There are no solutions.
Solution
Solution Steps
To solve the equation \(7 x^{2/3} - 48 x^{1/3} - 7 = 0\), we can use a substitution method. Let \(y = x^{1/3}\). Then the equation becomes a quadratic equation in terms of \(y\): \(7y^2 - 48y - 7 = 0\). We can solve this quadratic equation using the quadratic formula. Once we find the values of \(y\), we can substitute back to find the corresponding values of \(x\).
Step 1: Substitute and Simplify the Equation
To solve the equation \(7x^{2/3} - 48x^{1/3} - 7 = 0\), we first make a substitution. Let \(y = x^{1/3}\). This transforms the equation into a quadratic form:
\[ 7y^2 - 48y - 7 = 0 \]
Step 2: Solve the Quadratic Equation
We solve the quadratic equation \(7y^2 - 48y - 7 = 0\) using the quadratic formula:
\[ y = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} \]
where \(a = 7\), \(b = -48\), and \(c = -7\). The solutions for \(y\) are:
\[ y_1 = -0.1429 \]
\[ y_2 = 7.0000 \]
Step 3: Back-Substitute to Find \(x\)
Since \(y = x^{1/3}\), we find \(x\) by cubing the solutions for \(y\):
\[ x_1 = (-0.1429)^3 = -0.0029 \]
\[ x_2 = (7.0000)^3 = 343.0000 \]
Final Answer
The real solutions for the equation are:
\[ \boxed{-0.0029, 343.0000} \]
The correct choice is A: \(\{-0.0029, 343.0000\}\).