Element X is a radioactive isotope such that every 28 years, its mass decreases by half. Given that the initial mass of a sample of Element X is 80 grams, how long would it be until the mass of the sample reached 61 grams, to the nearest tenth of a year?

What is the value of x in the diagram below?

Select the conic section that represents the equation. 3x2 + 3y2 -2x + 4 = 0

Which statements describe the solutions to the inequality x< -20 check all that apply. there are infinite solutions. each solution is negative. each solution is positive. the solutions are both positive and negative. the solutions contain only integer values. the solutions contain rational number values.