-$\frac{29}{35}$
We are asked to find the value of $x$ that satisfies the given equation:
$5(5x^2 - 5) - 5(5x^2 + 7x - 2) = 14$
First, distribute the number 5 into each set of parentheses:
Substitute these back into the original equation:
$(25x^2 - 25) - (25x^2 + 35x - 10) = 14$
When removing the second set of parentheses, remember to change the sign of each term inside because of the minus sign in front:
$25x^2 - 25 - 25x^2 - 35x + 10 = 14$
Now, group and combine similar terms:
The equation simplifies to:
$0 - 35x - 15 = 14$
$ -35x - 15 = 14$
To isolate the term $-35x$, add 15 to both sides of the equation:
$ -35x - 15 + 15 = 14 + 15$
$ -35x = 29$
Finally, divide both sides by -35 to find the value of $x$:
$ x = \frac{29}{-35}$
$ x = -\frac{29}{35}$
Therefore, the value of $x$ that satisfies the equation is $-29/35$.