Выполните действия: (7/8-13/20)+9/10; (3/4-8/15)+17/20

( 7/8 - 13/20) + 9/10 = (35/40 - 26/40) + 9/10 = 9/40 + 36/40 = 45/40 = 9/8 = 1 1/8. ( 3/4 - 8/15) + 17/20 = ( 45/60 - 32/60) + 17/20= 13/60 + 51/60 = 64/60 = 32/30= 16/15= 1 1/15

(7/8-13/20)+9/10=1  1/8
1)7/8-13/20=35/40-26/40=9/40
2)9/40+9/10=9/40+36/40=45/40=1  1/8

(3/4-8/15)+17/20=
1)3/4-8/15=45/60-32/80=13/60
2)13/60+17/20=13/60+51/60=64/60=1  1/15