целая 8/21 + 5/7 2) 14/55 умножить 33/50 разделить 1 целая 24/25 3) 4(3х - 1 ) - 8( 2х + 5 )

1)
=9/42-1 16/42+30/42=
=39/42-58/42=-19/42
2)
=14/55×33/50÷49/25=
=3/5×7/25×25/49=3/5×1/7=3/35
3)
=12х-4-16х-40=-4х-44