A:speaking? understand
B:spoken; understand
C:speaking; understood
D:spoken; understood
已知集合M={x|x2+ax+b=0,x∈R}.
(Ⅰ)若集合M是单元素集,求实数a,b满足的关系式;
(Ⅱ)若1,3∈M,求实数a,b的值.