1 1/2 x 2 10/13 + 2 10/13 x 2 10/13 - 2 10/13 x 3 1/6 =

2 10/13 (1 1/2+2 10/13-3 1/6) = 2 10/13 * (3/2+36/13-19/6) = 36/13 ((117+216-247) / 78) = 36/13 (86/78) = 36/13 (43/39) = (36*43) / (13*39) = (12*43) / (13*13) = 516/169 = 3 9/169

проверь условие

=2 10/13 * (1 1/2+2 10/13 - 3 1/6) =

=36/13 * (3/2+36/13-19/6) =

=36/13 * (102/78+216/78 - 247/78) =

=36/13*71/78=2556/1014=2 528/1014=

=2 264/507

если нигде не ошиблась то так