Which expression is equivalent to −578?

You can model the population of a certain city between 1955-2000 by the radical function p(x)=55,000 sqrt x-1945. using this model, in which year was the population of that city 220,000

2-digit numbers less than 91 which are 1 less than a multiple of 10

Rewrite the hyperbolic equation 4y^2 -9x^2 +54x-8y-113=0