If m(x) = x^2 + 3 and n(x) = 5x + 9, which expression is equivalent to (mn)(x)?

45 was divided by a power of ten to get 4.5. what power of ten was it divided by? people 4.5

I’m on question 7 it says a covered water tank is in the shape of a cylinder the tank has a 28 inch diameter and a height of 66 inches to the nearest square inch what is the surface area of the water tank

An airplane travels at an unknown elevation before it descends 3 miles to an elevation of 15 miles. find the elevation of the plane before its descen.