A.2% B.1% C.2.5% D.0.5% E.5%
A.X1+X2或X1-X2 B.X1-X2 C.X1+X2與X1-X2均可以 D.X1+X2 E.以上都不對
A.1394 B.1375 C.1352 D.1275 E.以上都不對