8x+5(2-x)=13
(x-3)(5-x)>0
1) 8x+5*(2-x)=13 3) (x-3)*(5-x)>0
8x+10-5x=13 -1(x-3)*(x-5)>0 |*(-1)
3x=13-10 (x-3)*(x-5)<0 </p>
x=1 x∈(3;5)