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Solve 2x^(2) + 5x + 3 gt 0...

Solve `2x^(2) + 5x + 3 gt 0`

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To solve the inequality \(2x^2 + 5x + 3 > 0\), we will follow these steps: ### Step 1: Identify the quadratic expression We start with the inequality: \[ 2x^2 + 5x + 3 > 0 \] ### Step 2: Factor the quadratic expression We need to factor the quadratic expression \(2x^2 + 5x + 3\). We can rewrite it as: \[ 2x^2 + 2x + 3x + 3 > 0 \] Now, we can group the terms: \[ (2x^2 + 2x) + (3x + 3) > 0 \] Factoring out the common terms, we have: \[ 2x(x + 1) + 3(x + 1) > 0 \] Now we can factor by grouping: \[ (2x + 3)(x + 1) > 0 \] ### Step 3: Find the roots of the equation To find the intervals where the product is positive, we first find the roots of the equation \( (2x + 3)(x + 1) = 0 \): 1. Set \(2x + 3 = 0\): \[ 2x = -3 \implies x = -\frac{3}{2} \] 2. Set \(x + 1 = 0\): \[ x = -1 \] ### Step 4: Determine the intervals The roots divide the number line into intervals. The critical points are \(x = -\frac{3}{2}\) and \(x = -1\). The intervals to test are: 1. \( (-\infty, -\frac{3}{2}) \) 2. \( (-\frac{3}{2}, -1) \) 3. \( (-1, \infty) \) ### Step 5: Test the intervals We will choose test points from each interval to determine where the product is positive. 1. For the interval \( (-\infty, -\frac{3}{2}) \), choose \(x = -2\): \[ (2(-2) + 3)(-2 + 1) = (-4 + 3)(-1) = (-1)(-1) = 1 > 0 \] So, this interval satisfies the inequality. 2. For the interval \( (-\frac{3}{2}, -1) \), choose \(x = -1.25\): \[ (2(-1.25) + 3)(-1.25 + 1) = (-2.5 + 3)(-0.25) = (0.5)(-0.25) = -0.125 < 0 \] This interval does not satisfy the inequality. 3. For the interval \( (-1, \infty) \), choose \(x = 0\): \[ (2(0) + 3)(0 + 1) = (3)(1) = 3 > 0 \] This interval satisfies the inequality. ### Step 6: Combine the results The inequality \(2x^2 + 5x + 3 > 0\) holds in the intervals: \[ (-\infty, -\frac{3}{2}) \cup (-1, \infty) \] ### Final Answer Thus, the solution to the inequality \(2x^2 + 5x + 3 > 0\) is: \[ x \in (-\infty, -\frac{3}{2}) \cup (-1, \infty) \]
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