California is on the San Andreas Faultline.
There will always be a lot of Earthquakes in this region because two techtonic plates as slowly sliding past each other here.
Here is a video explaining plate techtonics.
The voice is childish but the information is good.
And here some info on the San Andreas fault.
The solutions to the equation 6x^2 + 10x = 4 - 10x - 6x^2 can be written in the form x=p+-sqrtQ/R where P and R are relatively prime integers and R>0. What is the product PQR ?
Just take it all to one side
then solve it with the quadratic equation.
From there it shouldn't be hard.
I have not done it so if there are problems that i have not noticed then you can let me. or others here, know.