Найдите значение выражения: (a+2b) ²/2 (a-4b) + (a-2b) ²/3 (4b-a) - 6ab+b²/2 (a-4b) при a=-7/6, b=1/6

(a + 2 b) ²/[2 (a - 4 b) ] + (a - 2 b) ²/[3 (4 b - a) ] - (6 a b + b²) / [2 (a - 4 b) ] =

= [3 (a + 2 b) ² - 2 (a - 2 b) ² - 3 (6 a b + b²) ]/[6 (a - 4 b) ] =

= (3 a² + 12 a b + 12 b² - 2 a² + 8 a b - 8 b² - 18 a b - 3 b²) / [6 (a - 4 b) ] =

= (a² + b² + 2 a b) / [6 (a - 4 b) ] = (a + b) ²/[6 (a - 4 b) ];

a = - 7/6; b = 1/6;

(a + b) ²/[6 (a - 4 b) ] = ( - 7/6 + 1/6) ²/[6 ( - 7/6 - 4 * 1/6) ] = ( - 1) ²/[6 * ( - 11/6) ] =

= 1 / ( - 11) = - 1/11.