Найдите значение выражения:

1) 6 (2x-3y) - 2 (x+y), если 2y-x=17,8

2) 7a (3b+4c) - 3a (b+1/3c), если a = - 3 1/3, 3c+2b = - 1,6

1) 6 (2x-3y) - 2 (x+y) = 12x-18y-2x-2y=10x-20y

2y-x=17,8|*10

20y-10x=178

10x-20y=-178

6 (2x-3y) - 2 (x+y) = 12x-18y-2x-2y=10x-20y=-178

2) 7a (3b+4c) - 3a (b+1/3c) = 21ab+28ac-3ab-ac=18ab+27ac=3a (6b+9c)

a = - 3 1/3, 3c+2b = - 1,6

3c+2b=-1,6|*3

9c+6b=-4,8

3a (6b+9c) = 3 * (-3 1/3) * (-4,8) = - 9 1/3 * (-4,8) = - 10 * (-4,8) = 48