A) 3/8
b)8/15y
в)-7y/9
г)x/2
2)x≠0 x≠1
X=yabloni
y=grushi
z=slivy
x+y+z=130
3y=x y+10=z
Togda poluchitsa x+y+z= 3y + y + y+10=130
5y+10=130
5y=120
(Grushi)y=24
(Yabloki)x=3y=72 (Slivy)z=y+10=34
<span>х - скорость катера </span>
<span>х+4 - скорость теплохода </span>
<span>48/х=48/(х+4)+1 </span>
<span>48/х=(48+х+4)/(х+4) </span>
<span>48х+48*4=48х+x^2+4x </span>
<span>192=4x+x^2 </span>
<span>x^2+4x-192=0 </span>
<span>D/4=4+192=14^2 </span>
<span>X1,2=-2+ -14 </span>
<span>X1<0 X2=12 </span>
<span>скор. катера 12 км/ч</span>
<span>скор. теплохода 16км/ч </span>