(1/4 - (1/4 + 1/9) : 1/9) * (2/3 + 7/15 : (0,4 - 1/6))

( 1/4 - 13/36 * 9) * (2/3 + 7/15 : (2/5 - 1/6))

(1/4 - 13/4) * (2/3 + 7/15 : 7/30)

-3(2/3 + 7/15 * 30/7)

-3(2/3 + 2)

-3 * 8/3

-8