-$\frac{19}{8}$
We are asked to find the value of $x$ that satisfies the equation: $3(2x^2 - 5) - 2(3x^2 + 4x - 8) = 20$
First, distribute the constants outside the parentheses into the terms inside them.
Substituting these back into the equation gives:
$6x^2 - 15 - 6x^2 - 8x + 16 = 20$Combine like terms on the left side of the equation.
After combining like terms, the equation simplifies to:
$-8x + 1 = 20$To isolate the term containing $x$, subtract 1 from both sides of the equation.
$-8x + 1 - 1 = 20 - 1$ $-8x = 19$Finally, divide both sides by -8 to find the value of $x$.
$\frac{-8x}{-8} = \frac{19}{-8}$ $x = -\frac{19}{8}$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.
The value of $x$ that satisfies the given equation $3(2x^2 - 5) - 2(3x^2 + 4x - 8) = 20$ is $x = -\frac{19}{8}$.