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Question

Find the value of x satisfying: $3(2x^2 - 5) - 2(3x^2 + 4x - 8) = 20$

The correct answer is

-$\frac{19}{8}$

Solving the Algebraic Equation

We are asked to find the value of $x$ that satisfies the equation: $3(2x^2 - 5) - 2(3x^2 + 4x - 8) = 20$

Step-by-Step Solution

  1. Expand the terms:

    First, distribute the constants outside the parentheses into the terms inside them.

    • Multiply 3 by each term in the first parenthesis: $3 \times 2x^2 = 6x^2$ and $3 \times (-5) = -15$.
    • Multiply -2 by each term in the second parenthesis: $-2 \times 3x^2 = -6x^2$, $-2 \times 4x = -8x$, and $-2 \times (-8) = 16$.

    Substituting these back into the equation gives:

    $6x^2 - 15 - 6x^2 - 8x + 16 = 20$
  2. Simplify the equation:

    Combine like terms on the left side of the equation.

    • Combine the $x^2$ terms: $6x^2 - 6x^2 = 0$. These terms cancel each other out.
    • Combine the constant terms: $-15 + 16 = 1$.
    • The term with $x$ is $-8x$.

    After combining like terms, the equation simplifies to:

    $-8x + 1 = 20$
  3. Isolate the x term:

    To isolate the term containing $x$, subtract 1 from both sides of the equation.

    $-8x + 1 - 1 = 20 - 1$ $-8x = 19$
  4. Solve for x:

    Finally, divide both sides by -8 to find the value of $x$.

    $\frac{-8x}{-8} = \frac{19}{-8}$ $x = -\frac{19}{8}$

Final Answer Verification

Let's check if $x = -\frac{19}{8}$ satisfies the original equation:

$3(2(-\frac{19}{8})^2 - 5) - 2(3(-\frac{19}{8})^2 + 4(-\frac{19}{8}) - 8)$ $= 3(2(\frac{361}{64}) - 5) - 2(3(\frac{361}{64}) - \frac{76}{8} - 8)$ $= 3(\frac{361}{32} - \frac{160}{32}) - 2(\frac{1083}{64} - \frac{608}{64} - \frac{512}{64})$ $= 3(\frac{201}{32}) - 2(\frac{-37}{64})$ $= \frac{603}{32} + \frac{74}{64}$ $= \frac{603}{32} + \frac{37}{32}$ $= \frac{640}{32} = 20$

The value $x = -\frac{19}{8}$ satisfies the equation.

Conclusion

The value of $x$ that satisfies the given equation $3(2x^2 - 5) - 2(3x^2 + 4x - 8) = 20$ is $x = -\frac{19}{8}$.

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Important Questions from Algebric Equations

  1. For what value of K is the equation \(\frac{0.009}{K} = 0.1\) true?
  2. Arnab buys 9 oranges and 8 bananas for ₹276. When the cost of an orange is decreased by 10% and that of a banana remains the same, then the cost of 5 oranges and 10 bananas is ₹210. What is the original cost of 4 oranges and 3 bananas?
  3. Find the value of x satisfying: $5(5x^2 - 5) - 5(5x^2 + 7x - 2) = 14$
  4. The product of two positive numbers is 3645. If the first number is five times the second number, then the sum of the two numbers is:
  5. The product of two positive numbers is 80. If the first number is five times of the second number, then the sum of the two numbers is:
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