3ac*5ab; 10x*9y * (-7a); b-6a-10b+9a+4b; 8m+2 - (5+7m) - 4m при m=17; 7 (y+2x) - 2 (x-2y); 2c - (3c + (2c - (c+1)) + 3)

3ac * 5ab = 15 а2cd;

10x * 9y * (-7a) = - 630 хуа;

b - 6a - 10b + 9a + 4b = - b - 10b + 4b - 6a + 9a = - 5b + 3a;

Если m = 17, то 8m + 2 - (5 + 7m) - 4m = 8 * 17 + 2 - (5 + 7 * 17) - 4 * 17 = 136 + 2 -

(5 + 119) - 68 = 138 - 124 - 68 = - 54;

7 * (y + 2x) - 2 * (x - 2y) = 7 у + 14 х - 2 х + 4 у = 11 у + 12 х;

2c - (3c + (2c - (c + 1)) + 3) = 2 с - (3 с + (2 с - с - 1) + 3) = 2 с - (3 с + с - 1 + 3) = 2 с - (4 с + 2) =

= 2 с - 4 с - 2 = - 2 с - 2 = - 2 * (с - 1).