(1 2/3:2 1/2)-(3/5×1 2/7) tolong kasih tau caranya

1 2/3 ÷ 2 1/2
= 5/3 ÷ 5/2
= 5/3 × 2/5
= 10/15
=2/3


3/5 × 1 2/7
= 3/5 × 9/7
= 27/35

2/3-27/35
= 2×70 - 27×6/210
=140-162/210
= -22/210
=-11/105