The half life of radium-226 is 1590 years. If sample contains 400mg how much remains after 3000 years

Ily begins solving the equation 4(x – 1) – x = 3(x + 5) – 11. her work is shown below. 4(x – 1) – x = 3(x + 5) – 11 4x – 4 – x = 3x + 15 – 11 3x – 4 = 3x + 4 how can her partial solution be interpreted?

Ill mark the brainliest if you me with the these three questions 7,8,9

Which of these numbers of simulations of an event would be most likely to produce results that are closest to those predicted by probability theory? 15, 20, 5, 10