0,5*5-4=2,5-4=-1,5
0,6*5-3=3-3=0
=> -1,5 < 3
________________
<span>6,3x-4-3(7,2x+0,3) = 6,3х-4-21,6х-0,9 = -15,3х-4,9
</span>х=2/3
<span> -15,3 * 2/3 - 4,9 = -10,2 - 4,9 = - 15,1 </span>
9-7x-21=5-4x; -12-7x=5-4x; -7x+4x=5+12; -3x=17; x= -17/3.
1/x<1/2
1/x-1/2<0
(2-x)/2x<0
x=2 x=0
x∈(-∞;0) U (2;∞)