A.4 B.5 C.6 D.7
A.32548.5 B.32,548.5 C.032,548.50 D.32,548.50
A.A=C:C=B :B=A B.A=A+B:B=A–B:A=A–B C.A=B:B=A D.A=(A+B)/2:B=(A - B)/2