Question

зделать два задания нужно срочно !!!!

Answer 1

1
√(x+20)≥x
x+20≥0⇒x≥-20
x+20≥x²
x²-x-20≤0
x1+x2=1 U x1*x2=-20
x1=-4 U x2=5
-4≤x≤5
x∈[-4;5]
2
(2log(5)6-log(5)4)/(log(5)15-1)=(log(5)36-log(5)4)/(log(5)15-log(5)5)=
=log(5)(36/4)/log(5)(15/3)=log(5)9/log(5)3=log(3)9=2