Verified answer

Ответ:

Пошаговое объяснение:

№1

1) 9(7х-6)-18х = 63х-54-18х = 45х-54

2) 7а-6(19-а) = 7а-114=6а = 13а-114

3) 0,8(6х-2)+1,6(х-4) = 4,8х-1,6+1,6х-6,4= 6,4х-8
4) 2,8(5b-6c)-(7b-8a)*1,2 = 14b-16.8c-(8,4b-9,6a) = 5,6b-16,8c-9,6a

5)-(-4,9-5,8z)-(3,1z-5,6) = 4,9+5,8z-3,1z+5,6 = 10,5 +2,7z

6) 8/15 (2 1/4a-7 1/2b)-7/30(4 2/7a-8 4/7b) = 8/15 (9/4a-15/2b) - 7/30(30/7a-60/7b) = 6/5a-4b-a+2b = 1/5a-2b

№2

1) 0.6(4* 2 4/13-18)-0.4(5-7 * 2 4/13) = 3/5(4*30/13-18) - 2/5(5-7* 30/13) = 3/5(120/13-18)-2/5(5-210/13) = 3/5(-114/13 - 2/5(-145/13) = -345/65+2*29/13 = -342/65 + 58/13 = -4/5

2) 5 1/4 (12-(-0.4))- 3 3/4(- (-0.4)-24) = 21/4(12+0.4) - 15/4(0.4-24) = 21/4 * 12.4 - 15/4 * (-23.6) = 21/4 * 62/5- 15/4 * (-118/50) = 21/2 * 31/5 + 3/2 * 59 = 651/10+177/2 = 768/5 = 153 3/5