Element X is a radioactive isotope such that every 4 years, its mass decreases by half. Given that the initial mass of a sample of Element X is 300 grams, how long would it be until the mass of the sample reached 90 grams, to the nearest tenth of a year?​

Find the volume of the solid obtained by rotating the region enclosed by the curves y=1x and y=7^-x about the x-axis. (use symbolic notation and fractions where needed.) volume =

Which statements about the system are true? check all that apply. y =1/3 x – 4 3y – x = –7 the system has one solution. the system consists of parallel lines. both lines have the same slope. both lines have the same y–intercept. the equations represent the same line. the lines intersect.

Question 4 of 102 pointsjuliana had $96, which is eight times as much money as al had. how mucmoney did al have? select the correct solution method below, representingals money with x.