Question

1. Решите неравенство
а) $( sqrt[3]{8}) ^{x+6} textgreater frac{1}{9}$
b) ($(1 frac{2}{7} ) ^{ x^{2} - 4} leq 1$

2. Решите систему 
 $left { {{x+y=-2} atop 6 ^{x+5y} {=36}} right.$

Answer 1

1
a)2^(x+6)>1/9
x+6>log(2)1/9
x>-6-log(2)9
b)(9/7)^(x²-4)≤1
x²-4≤0
(x-2)(x+2)≤0
x=2 u x=-2
x∈[-2;2]
2
x+y=-2⇒x=-2-y
6^(x+5y)=36⇒x+5y=2
-2-y+5y=2
4y=4
y=1
x=-2-1=-3
(-3;1)