Найдите область определения функции y=√(0,5)^x -8

[tex]y=\sqrt{0,5^{x}-8}\\\\oof: \; \; 0,5^{x}-8\geq 0\; \; ,\; \; 2^{-x}\geq 2^3\; \; ,\; \; -x\geq 3\; \; ,\; \; x\leq -3\\\\x\in (-\infty ,-3\, ][/tex]

2х+2у=

pusti budet x i y storoni preamougolinovo

{2x+2y=26,x*y=36

{x+y=13,x*y=36

{x=13-y,(13-y)y=36

{x=13-y,13y-y^2=36

{x=13-y,y^2+13y-36=0

y^2+13y-36=0

d=169-4*1*(-36)=25

y1=-13-5/2=-9

y2=-13+5/2=4

{x=13-4=9,y=4

otvet: storoni preamougolinika rovni 4 cm i 9 cm