Element X is a radioactive isotope such that every 61 years, its mass decreases by half. Given that the initial mass of a sample of Element X is 20 grams, how long would it be until the mass of the sample reached 16 grams, to the nearest tenth of a year?

Which equation represents the line that passes through the points and (4, 10) and (2, 7)? y = 3/2x - 11y = 3/2x +4y = - 3/2x + 19y = - 3/2x + 16

Thomas is using a drawing program to complete a construction. which construction could he be completing? two perpendicular lines are drawn. inscribing an equilateral triangle in a circle inscribing a square in a circle inscribing a regular pentagon in a circle inscribing a regular hexagon in a circle

Deena is planting two rectangular gardens. one garden is 3.67 feet by 8.56 feet, and the other garden is 3.67 feet by 7.45 feet. which expression does not respresent the total area in square feet of the two gardens