<span>у=-х2+2х-1
y=-2x+2x-1
y=0-1
y=-1, x</span>∈R<span>
</span>
<span>x/3 + x/5=8 x(1/3+1/5)=8 8/15x=8 x=15
</span><span>y/3 + y/4 = 14 y(1/3+1/4)=14 7/12y=14 y=14*12/7=24</span>
2 ^(2- log₂5 )+ 1/2^(log₂5)= 2² /2^log₂5 ) + 2^-1*(log₂5) = 4/5 + 1/5 =5/5 =1