What is the vertex and equation of directrix of the parabola x²-8y+4x=0​

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.

Assume that adults have iq scores that are normally distributed with a mean of mu equals 100 and a standard deviation sigma equals 20. find the probability that a randomly selected adult has an iq between 80 and 120.assume that adults have iq scores that are normally distributed with a mean of mu equals 100 and a standard deviation sigma equals 20. find the probability that a randomly selected adult has an iq between 80 and 120.

At the beginning of the month, alexa’s bank account contained $4329.97. she then made two deposits of $452.28 each and a withdrawal of $279.34. she then went to the store and bought the new iphone x for $1,015 plus 6% sales tax. how much money does she have in her account now?