Răspunsuri

2014-11-17T22:24:03+02:00
a)2^x≤8
2^x≤2^3

x≤3⇒x∈{0,1,2,3}

b)11^2x+1<11^7
2x+1<7

2x<7-1

2x<6

x<6:2

x<3⇒x∈{0,1,2}

c)13^x-2>13^2001
x-2>2001

x>2001+2
x>2003⇒x∈{2004,2005,2006.....}

d)9^x+1≤3^12
9^x+1≤(3^2)^6

x+1≤6
x≤5⇒x∈{0,1,2,3,4,5}