What is the percent of change from 5,000 to 2,000

Tim's phone service charges $23.06 plus an additional $0.22 for each text message sent per month. if tim's phone bill was $28.56, which equation could be used to find how many text messages, x, tim sent last month?

The number of fish in a lake can be modeled by the exponential regression equation y=14.08 x 2.08^x where x represents the year

Evaluate the discriminant of each equation. tell how many solutions each equation has and whether the solutions are real or imaginary. 4x^2 + 20x + 25 = 0