The half-life of radium-226 is 1590 years. If a sample contains 400 mg how many mg will remain after 4000 years?

Asap i need it now choose all the answers that apply. sex-linked disorders affect males more than females affect females more than males can be carried by females, without being expressed are always expressed in males are caused by genes carried on the x and y chromosomes

4+(2+x) can you me solve this problem

X+y=-4 x-y=2 use elimination with adding and subtraction