What is the following difference?
2ab(V192ab?)-s(/81a*b*
-3ab[3ab?
16ab? (1/3a) - 45a_b? (2/3)
-7a6f3ad?
Bab V3ab? ) - 15ab? (1/320)

answer:  

\boxed {\frac{1}{5}}  

━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

solution-

60 *   \frac{1}{5}   = 12

90 * \frac{1}{5} = 18

75 * \frac{1}{5} = 15

━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

hence, the answer would be \boxed {\frac{1}{5}}