1) 5a/16 - a/24= (120a/384) - (64a/384)= (120a - 64a) / 384= 56a / 384= 7a / 48
2) 4/b + 7/5b= (20 + 7b) / 5b
3) 28c/d² × d / 21c= 28c/21c= 4/3
4) 12x³/25y ÷ 9x²/10y= 12x³/25y * 10y/9x²= 120xy / 225x²= 4y / 15x
1) 5a/16 - a/24
= (120a/384) - (64a/384)
= (120a - 64a) / 384
= 56a / 384
= 7a / 48
2) 4/b + 7/5b
= (20 + 7b) / 5b
3) 28c/d² × d / 21c
= 28c/21c
= 4/3
4) 12x³/25y ÷ 9x²/10y
= 12x³/25y * 10y/9x²
= 120xy / 225x²
= 4y / 15x