Three fourths of a number decreased by nine is at least forty two

Customers at an ice-cream shop took a survey .the results showed that 144 customers rated the shop as being "very satisfactory ."this number represented 45%of the total nunber of customers who took the survey

The parabola x = y² - 9 opens: a.)up b.)down c.) right d.)left

Which expression do you get when you eliminate the negative exponents of 4a^2 b^216a^-3 b