k=7/3-4/3+8/5
= 7-4/3+8/5
= 1+8/5
= 5/5+8/5
= 13/5
N=-7/5÷(2/9-7/18)
=-7/5÷(4/18-7/18)
=-7/5÷3/18
=-7/5×6/1
=-42/5
L=-4/9×1/5÷7/3
=-4/45÷7/3
=-4/45×3/7
=-12/315
=-4/105
O=(4/5+-3/2)÷(-9/4-1/6)
=-7/10÷-29/12
=-7/10÷12/-29
=84/290
=42/145
M=-1/5÷-5/6+7/5
=-1/5×6/-5+7/5
=6/25+7/4
=199/100
P=(5/7-5/3)÷(21/25÷14/30)
=-20/21÷9/5
=-20/21×5/9
=-100/189