Simplify 67 × 66 / 65, 12 / 5 / 9 + 12 / 5 / 8 / 9

Simplify 67 × 66 / 65, 12 / 5 / 9 + 12 / 5 / 8 / 9

=(66+1)*(65/66)
=65+(65/66)
=65 and 66 out of 65
=(5/12)*(1/9)+(5/12)*(8/9)
=(5/12)*1
=5/12