Simple operation of 1 / 2 × 11 / 20 + 1 / 2 × 20 / 49

Simple operation of 1 / 2 × 11 / 20 + 1 / 2 × 20 / 49

1/2×11/20+1/2×20/49
=1/2*(11/20+20/49)
=1/2*(11*49+20*20)/(20*49)
=939/1960