What is 810,000 into scientific notation

Find dy/dx using implicit differentiation ln(20+e^xy)=y

Monthly water bills for a city have a mean of $108.43 and a standard deviation of $32.09. find the probability that a randomly selected bill will have an amount greater than $155, which the city believes might indicate that someone is wasting water. would a bill that size be considered unusual?

For what values of the variable x is the expression square root of 7x+14+ square root of 7-x a real number?