=SUMIF(A2:A7,"A",B2:B7)=SUMIF(A2:A7,"B",B2:B7)
B9单元输入：=SUMIF($A$2:$A$8,LEFT(A9),$B$2:$B$8)下拉公式
=sumif($A$2:$A$7,A9,$B$2:$B$7)
