You can solve quadratic equations with the p-q formula. Swedish National Test
Formula Collection
I hope you know that x^2 is the same as x²? Otherwise check "Skriva
Ma på dator"
(there is also described how you can write characters like ^ =
* / < > ( ) with a keyboard)

-5x^{2}
- 4x = - 9 is not in the right form: x² + px + q=0, What would make the x²
term not have - 5 as coefficient?

Divide both sides with - 5!

x^{2}
- 4x/(-5) = - 9/(-5) should have the signs sorted out and still doesn't have 0 in the right side (which fits the standard Swedish form).

DO NOT READ ANY MORE HINTS BEFORE YOU HAVE REALLY TRIED TO USE THE HINTS ABOVE AND TESTED YOUR ANSWER. But it you still aren't getting anywhere, look at more hints. There are about 12 hints, all told.