P U Q = {8, 10, 12, 17, 21, 25, 28, 30}
P U R = {8, 10, 12, 17, 21}
(P U Q) \ (P U R) = {25, 28, 30}
AD=AH+HD=3+30=33
BH^2=BD^2-HD^2
BH^2=50^2-30^2
BH^2=1600
BH=40
Sпар= AD*BH=33*40=1320
ОТВЕТ= 1320
X/5+x/3-27=0
3x/15+5x/15-405=0
8x=405
x=405/8=50,625
D=b^2-4ac=25-4*3*4=-23<0 корней нет