3x^2-x-2=0
D= (-1)^2-4*3*(-2)= 25
x1= 1-5/6= -2/3
x2= 1+5/6= 1
..............................
SΔABC=1/2·BC·h;
Sтрап=(AD+BC)/2·h;⇒h=2·Sтрап/(AD+BC);
h=2·27/(6+3)=54/9=6;
SΔABC=1/2·3·6=9;
√[a-b]/5=√[0.25-0.09]/5=√0.16/5=0.4/5=0.08
= (3a - 4a) + (5b - 2b) = -a + 3b = -5,3 + 3 * 1/3 = -5,3 + 1 = -4,3
Ответ: -4,3.