I need help with trigonometry

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

Hey hotel charges guests $19.75 a day to rent five video games at this rate which expression can be used to determine the charge for renting nine video games for one day at this hotel? pls

Out of 50 students surveyed, 16 have a dog. based on these results, predict how many of the 280 students in the school have a dog.