19×7／9＋11×19／9=19 x 7/9 +19 x 11/9=19x(7/9+11/9)=19x2=382／9×3／8÷6／7=(2/9)x(3/8)x(7/6)=7/7215×4／21＋8／7÷16=15x4/3x(1/7)+(1/7)x8x(1/16)=20x(1/7)+(1/7)x(1/2)=20/7+1/14=41/14