Ответы и объяснения

2014-01-25T17:48:32+04:00
№207
4)4(y-5)+3(y+7)=4y-20+3y+21=y+1
5)7(n-9)-5(n+1)=7n-63-5n-5=2n-68
6)11(a-9)+8(a-13)=11a-99+8a-104=19a-203
№208
2)7(2x-y-4)-3(5x-3y-9)=14x-7y-28-15x+9y+27=-x+2y-1
4)9(2p-4q-7)+5(7q-4p+13)=18p-36q-63+35q+20p+65=38p-1+2
6)7(2y-x)-((5y-3x)-4(x+y))=14y-7x-5y+3x+4x-4y=5y
2014-01-25T17:49:40+04:00
N207
4)4y-20+3y+21=y+1
5)7n-63-5n-5=2n-68
6)11a-99+8a-104=19a-203

N208
2) 14x-7y-28-15x+9y+27=-x+2y-1
4)18p-36q-63+35q+20p+65=38p-1+2
6)14y-7x-5y+3x+4x-4y=5y
Держи ;)