(3/4+1/20)×1/2; 5/6×9/15-5/12×4/15;

Question

(3/4+1/20)×1/2; 5/6×9/15-5/12×4/15;

Answer 1

(3/4+1/20)*1/2=(15/20+1/20)*1/2=16/20*1/2=8/20=2/5

5/6*9/15-5/12*4/15=1-1/9=9/9-1/9=8/9