С+15=69+28
C+15=97
C=97-15
C=82
B-19=16+14
B-19=30
B=30+19
B=49
-(7-3y)=8-8(2-y) -5(2-2x)=2(x-3)+4 2x-4(x+7)=3(2-x)
-7+3y=8-16+8y -10+10x=2x-6+4 2x-4x-28=6-3x
3y-7=8y-8 10x-2x=-6+4+10 2x-4x+3x=6+28
3y-8y=-8+7 8x=8 x=34
-5y=-1 x=1
y=1/5
8*(3т - 2)-13=5*(12+3т)+28
24т-16-13=60+15т+28,
24т-15т=16+13+60+28,
9т=117,
т=13.
Ответ: 13.