Which two values of x are roots of the polynomial below? x2 - 11x + 13

Find the center and the radius of the circle with the equation: x^2-2x+y^2+4y+1=0?

With finding limits of multi variable !

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.