Найдите значение выражения 1) (3/16+a)- 3/8, a=5/12; 2) (b+5/6) - 3/4, b =11/12; 3) (4/15+5/8) - c, c= 3/5; 4) (1/5+d) - 9/20, d=13/16; !

1) (3/16+5/12)-3/8=(18/96=40/96)-3/8=58/96-3/8=58/96-26/96=32/96=1/3

2) (11/12-5/6)-3/4=(11/12-10/12)-3/4=1/12-3/4=1/12-9/12=- 2/3

3) (4/15+5/8)-3/5=(32/120+75/120)-3/5=105/120-3/5=7/8-3/5=35/40-24/40=11/40

4) (1/5+13/16)-9/20=(16/80+65/80)-9/20=81/80-9/20=81/80-36/80=45/80=3/16