5. y=k/x
-9=k/3
k=-9*3=-27
<span>y=-27/x</span>
7a-4в-4ву+7ау=7а(1+у)-4в(1+у)=(7а-4в)(1+у)
1/36^-x=6^-2
(6^-2)^-x=6^-2
6^2x=6^-2
2x=-2 => x=-1
Решение
<span>3^(x-3) + (1/3)*3^x > 10
(1/27)*(3^x) </span>+ (1/3)*3^x > <span>10 умножим на 27
3^x + 9*(3^x) > 270
10*(3^x) > 270
3^x > 27
3^x > 3</span>³
<span>так как 3 > 1, то
x > 3
x </span><span>∈ (3; + ∞)</span>