Element X is a radioactive isotope such that every 22 years, its mass decreases by half. Given that the initial mass of a sample of Element X is 50 grams, how long would it be until the mass of the sample reached 41 grams, to the nearest tenth of a year? HEL IM IN 11th grade

Nine more than four times a number is the same as one less than twice the number. find the number?

If x = -2, then x 2-7x+10 equals a. 0 b.20 c.28

Is there a direction u in which the rate of change of f(x,y)equals=x squared minus 3 xy plus 4 y squaredx2−3xy+4y2 at p(1,2) equals 14? give reasons for your answer. choose the correct answer below. a. no. the given rate of change is smaller than the minimum rate of change. b. no. the given rate of change is larger than the maximum rate of change. c. yes. the given rate of change is larger than the minimum rate of change and smaller than the maximum rate of change.