Home
Class 14
MATHS
If (13x^(2) + 30 x + 17)/(3x^(2) + 14 x ...

If `(13x^(2) + 30 x + 17)/(3x^(2) + 14 x + 8) gt 3`, then find the value of x, if `x in R` and `x ne (-2)/(3), -4`.

A

`(-oo, -4) cup ((-2)/(3), (7)/(2)) cup ((9)/(2), oo)`

B

`(-oo, -4) cup ((-2)/(3), (-1)/(2)) cup ((7)/(2), oo)`

C

`(-4, (-2)/(3)) cup ((-1)/(2), (7)/(2))`

D

None of these

Text Solution

AI Generated Solution

The correct Answer is:
To solve the inequality \(\frac{13x^2 + 30x + 17}{3x^2 + 14x + 8} > 3\), we can follow these steps: ### Step 1: Rewrite the Inequality We start with the inequality: \[ \frac{13x^2 + 30x + 17}{3x^2 + 14x + 8} > 3 \] Subtract 3 from both sides: \[ \frac{13x^2 + 30x + 17}{3x^2 + 14x + 8} - 3 > 0 \] ### Step 2: Combine the Terms To combine the terms, we need a common denominator: \[ \frac{13x^2 + 30x + 17 - 3(3x^2 + 14x + 8)}{3x^2 + 14x + 8} > 0 \] This simplifies to: \[ \frac{13x^2 + 30x + 17 - (9x^2 + 42x + 24)}{3x^2 + 14x + 8} > 0 \] Combining the terms in the numerator: \[ \frac{(13x^2 - 9x^2) + (30x - 42x) + (17 - 24)}{3x^2 + 14x + 8} > 0 \] This gives: \[ \frac{4x^2 - 12x - 7}{3x^2 + 14x + 8} > 0 \] ### Step 3: Factor the Numerator and Denominator Next, we need to factor the numerator \(4x^2 - 12x - 7\) and the denominator \(3x^2 + 14x + 8\). 1. **Numerator**: We can use the quadratic formula to find the roots: \[ x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a} = \frac{12 \pm \sqrt{(-12)^2 - 4 \cdot 4 \cdot (-7)}}{2 \cdot 4} \] \[ = \frac{12 \pm \sqrt{144 + 112}}{8} = \frac{12 \pm \sqrt{256}}{8} = \frac{12 \pm 16}{8} \] This gives us the roots: \[ x = \frac{28}{8} = 3.5 \quad \text{and} \quad x = \frac{-4}{8} = -0.5 \] Thus, the numerator factors to: \[ 4(x - 3.5)(x + 0.5) \] 2. **Denominator**: We can also use the quadratic formula for the denominator: \[ x = \frac{-14 \pm \sqrt{14^2 - 4 \cdot 3 \cdot 8}}{2 \cdot 3} = \frac{-14 \pm \sqrt{196 - 96}}{6} = \frac{-14 \pm \sqrt{100}}{6} \] This gives us: \[ x = \frac{-14 \pm 10}{6} \] Thus, the roots are: \[ x = \frac{-4}{6} = -\frac{2}{3} \quad \text{and} \quad x = \frac{-24}{6} = -4 \] The denominator factors to: \[ 3(x + 4)(x + \frac{2}{3}) \] ### Step 4: Set Up the Inequality Now we can rewrite the inequality: \[ \frac{4(x - 3.5)(x + 0.5)}{3(x + 4)(x + \frac{2}{3})} > 0 \] ### Step 5: Find Critical Points The critical points are: - From the numerator: \(x = 3.5\) and \(x = -0.5\) - From the denominator: \(x = -4\) and \(x = -\frac{2}{3}\) ### Step 6: Test Intervals We will test the sign of the expression in the intervals defined by the critical points: 1. \( (-\infty, -4) \) 2. \( (-4, -\frac{2}{3}) \) 3. \( (-\frac{2}{3}, -0.5) \) 4. \( (-0.5, 3.5) \) 5. \( (3.5, \infty) \) ### Step 7: Determine Where the Expression is Positive After testing these intervals, we find that the expression is positive in the following intervals: - \( (-\infty, -4) \) - \( (-\frac{2}{3}, -0.5) \) - \( (3.5, \infty) \) ### Step 8: Write the Final Solution Thus, the solution to the inequality is: \[ x \in (-\infty, -4) \cup \left(-\frac{2}{3}, -0.5\right) \cup (3.5, \infty) \] with the restrictions that \(x \neq -\frac{2}{3}\) and \(x \neq -4\).
Promotional Banner

Topper's Solved these Questions

  • INEQUALITIES

    DISHA PUBLICATION|Exercise Test Yourself|15 Videos
  • INEQUALITIES

    DISHA PUBLICATION|Exercise Practice Exercises (Standard Level)|19 Videos
  • GEOMETRY

    DISHA PUBLICATION|Exercise TEST YOURSELF |3 Videos
  • INTEREST

    DISHA PUBLICATION|Exercise Test Yourself|15 Videos

Similar Questions

Explore conceptually related problems

If 5x-2y = 17 and 3x +y =8 , then find the values of x and y .

if x+1,3x and 4x+2 are in AP then find the value of x

If 2x+1,3x+2 and 4x+3 are in A.P.then find the value of x'.

If f(x)=2x^(3)-13x^(2)+17x+12 , then find the value of f(-2) and f(3).

If x in N and |[x+3,-2],[-3x,2x]|=8, then find the value of x

If 3 ( 5x - 7) - 4 ( 8x - 13) = 2 ( 9x - 11) - 17, then the value of ( 7x - 5)/(11 x - 9) is