a1=1,d=a2-a1=5-1=4an=a1+d(n-1)=1+4(n-1)=4n-3a10=4*10-3=37S12=na1+1/2n(n-1)d=12*1+1/2*12*11*4=12+264=276
a1=1 d=4S10=10*1+10*9*4/2=190S12=12*1+12*11*4/2=276
D=4 A1=1A10=A1+D（10-1）=1+4*9=37以此类推，S12=276
