<span>(x+2)(5x+3)-5(x+2)(x-2)⩽10
</span>
5х²+10х+3х+6-5х²+20≤10
13х≤-16
х≤-16/13
х∈(-∞;-16/13]
<span />
5х-6у=16/*13⇒65х-78у=208
7/2х+13/4у=16 1/6⇒42х+39у=194/*2⇒84х+78у=388
149х=596
х=596:149
х=4
20-6у=16
6у=20-16=4
у=4/6=2/3
(4;2/3)
S1=60кмV1=x-20S2=135кмV2=x+30t1=t260/(x-20)=135/(x+30)135x-2700=60x+180075x=4500x=60V1=60-20=40V2=60+30=90