Murray Murray
02/12/2023 · Primary School

16. \( x^{2}+3 x-m-2=0, \operatorname{C} K(S S)=\left\{x_{1}, x_{2}\right\} \) \( 2 x_{1}+x_{2}=-4 \Rightarrow m=? \)

UpStudy ThothAI Solution

Tutor-Verified Answer

Step-by-step Solution

To solve for \( m \) in the equation \( x^2 + 3x - m - 2 = 0 \) given the condition \( 2x_1 + x_2 = -4 \), we start by using Vieta's formulas. According to Vieta's, for a quadratic equation of the form \( ax^2 + bx + c = 0 \), the sum and product of the roots \( x_1 \) and \( x_2 \) are given by: \[ x_1 + x_2 = -\frac{b}{a} \quad \text{and} \quad x_1 x_2 = \frac{c}{a} \] In our case, we have: - \( a = 1 \) - \( b = 3 \) - \( c = -m - 2 \) Thus, we can write: \[ x_1 + x_2 = -\frac{3}{1} = -3 \] \[ x_1 x_2 = \frac{-m - 2}{1} = -m - 2 \] Now, we also have the condition \( 2x_1 + x_2 = -4 \). We can express \( x_2 \) in terms of \( x_1 \): \[ x_2 = -4 - 2x_1 \] Next, we substitute \( x_2 \) into the equation for the sum of the roots: \[ x_1 + (-4 - 2x_1) = -3 \] Simplifying this gives: \[ x_1 - 4 - 2x_1 = -3 \] \[ -x_1 - 4 = -3 \] \[ -x_1 = 1 \quad \Rightarrow \quad x_1 = -1 \] Now, substituting \( x_1 = -1 \) back into the equation for \( x_2 \): \[ x_2 = -4 - 2(-1) = -4 + 2 = -2 \] Now we have the roots \( x_1 = -1 \) and \( x_2 = -2 \). We can now find \( m \) using the product of the roots: \[ x_1 x_2 = -m - 2 \] \[ (-1)(-2) = -m - 2 \] \[ 2 = -m - 2 \] Solving for \( m \): \[ 2 + 2 = -m \] \[ 4 = -m \quad \Rightarrow \quad m = -4 \] Thus, the value of \( m \) is \[ \boxed{-4} \]

Quick Answer

The value of \( m \) is -4.
Answered by UpStudy AI and reviewed by a Professional Tutor
UpStudy ThothAI
Self-Developed and Ever-Improving
Thoth AI product is constantly being upgraded and optimized.
Covers All Major Subjects
Capable of handling homework in math, chemistry, biology, physics, and more.
Instant and Accurate
Provides immediate and precise solutions and guidance.
Try Now
Ask Tutors
Ask AI
10x
Fastest way to Get Answers & Solutions
By text

Enter your question here…

By image
Re-Upload
Uploaded Files
xxxx.png0%
Submit
📸 STUDY CAN BE A REAL STRUGGLE
Why Not UpStudy It?
Select your plan below
Premium

You can enjoy

  • Step-by-step explanations
  • 24/7 expert live tutors
  • Unlimited number of questions
  • No interruptions
  • Full access to answer and
    solution
Basic
  • Limited Solutions