( 13¹/₂₁ - 9²/₇ ) : ( 8³/₇ - 5½ ) =3 16/21:2 13/14=1 35/123
d) 14⅕ : 12⅗ - 3¹/₃ * ( 4 - 3½) =1 8/63-3¹/₃ *0.5=
1 8/63-1 2/3=-34/63
e) 1⅖ : 12³/₇ - 3¹/₃* ( 4²/₁₁ - 3½) =49/435-3¹/₃* 15/22=
49/435-2 3/11=-2 766/4785
f) 11⅖ * 12³/₇ - 3¹¹/₁₃ : ( 4⅖ - 2⅔) =141 24/35-3¹¹/₁₃:7 1/15=
141 24/35-375/689≈141.1