1) 0,3(1,2x-0,5y)-1,5(0,4x-y)=0,36x-0,15y-0,6x+1,5y=0,3y+1,35
2) -2,4(2,5a-1,5b)+0,5(1,8b+5,6a)=-6a+3,6b+0,9b+2,8a=-3,2a+4,5b
3) -1,8(3,5m-5)-6,5(0,8-0,4m)=-6,3m+9-5,2+2,6m=-3,7m+3,8
4) 4/9 (1.1/2c - 3/8) - ( 1.5/6 - 1.1/3c)=4/9 (3/2c - 3/8) - (11/6 - 4/3c) =
4/9 (12/8c - 3/8) - (11/6 - 8/6c)= 4/9 (9/8c - 3/6c)=4/9 (9/8c - 4/8c)=4/9*5/8c = 5/18c
5) 1,2(5/6k + 0,4n) - 1,8(5/9k - 0,3n)=6/5 (5/6k +2/5n) - 9/5(5/9k - 3/10n)=
k +12/25n -k+27/50n= 24/50n+27/50n=51/50n=1.1/50 n
6) (1/6 a + 6,5) - ( 2 7/9a + 3 1/3)=1/6 a + 13/2 - 25/9a - 10/3=
3/18 a + 39/6 - 50/18a - 20/6 =-47/18a+19/6=-2.11/18a+3.1/6
7) 3/7(0,56x - 4,9y) - 6/13( 0,52x - 3,9y)=
3/7(56/100x - 49/10y) - 6/13(52/100x - 39/10y)=
=0,38x-2,1y-0,24x+1,8y=0,14x-0,3y
1) 0,3(1,2x-0,5y)-1,5(0,4x-y)=0,36x-0,15y-0,6x+1,5y=0,3y+1,35
2) -2,4(2,5a-1,5b)+0,5(1,8b+5,6a)=-6a+3,6b+0,9b+2,8a=-3,2a+4,5b
3) -1,8(3,5m-5)-6,5(0,8-0,4m)=-6,3m+9-5,2+2,6m=-3,7m+3,8
4) 4/9 (1.1/2c - 3/8) - ( 1.5/6 - 1.1/3c)=4/9 (3/2c - 3/8) - (11/6 - 4/3c) =
4/9 (12/8c - 3/8) - (11/6 - 8/6c)= 4/9 (9/8c - 3/6c)=4/9 (9/8c - 4/8c)=4/9*5/8c = 5/18c
5) 1,2(5/6k + 0,4n) - 1,8(5/9k - 0,3n)=6/5 (5/6k +2/5n) - 9/5(5/9k - 3/10n)=
k +12/25n -k+27/50n= 24/50n+27/50n=51/50n=1.1/50 n
6) (1/6 a + 6,5) - ( 2 7/9a + 3 1/3)=1/6 a + 13/2 - 25/9a - 10/3=
3/18 a + 39/6 - 50/18a - 20/6 =-47/18a+19/6=-2.11/18a+3.1/6
7) 3/7(0,56x - 4,9y) - 6/13( 0,52x - 3,9y)=
3/7(56/100x - 49/10y) - 6/13(52/100x - 39/10y)=
=0,38x-2,1y-0,24x+1,8y=0,14x-0,3y
2) 3000 - 10% = 3000*0,9 = 2700 руб стоит 1 кг яблок после снижения цены на 10%
3) 27000/2700 = 10 кг яблок можно купить на те же деньги после снижения цены на 10 %
ответ: 10 кг