“모든 조건 충족되고 아이는 없습니다. 이런경우 EIC (line64a) 로 얼마를 계상 하면 되나요.”-->Hard to tell UNLESS you give your financial info on Sch SE for EIC W/S B. Your Earned Income and AGI, NOT MAGI, must each be less than $18,740 married filing jointly with no qualifying children. You need to file your EIC W/S. For example, on EIC table, For example, ASSUME that if the amount you are looking up is $4300(at least) and $4,350(But less than), then, your EIC amount is $331.
Please visit the IRS Website here and follow the instructions here; http://apps.irs.gov/app/eitc2011/Forward_Eligibility.do;jsessionid=GX7BPYsY3Yw3xDTTT9JRXHc2f5NBDPlyS9JJzQrJSy8bP7Xz20NL!-1569132604!-297738458
“ 그리고 부부 각각 net earning 이 $3270 & $1500 인데 SS credit 은 얼마가 계산되는지요.”---->You need to contact Soc Sec Adm.
http://www.ssa.gov/pgm/reach.htm