Question

EX 3 ȘI EX 5 VA ROG MULT DAU COROANA CAT DE REPEDE DACĂ SE POATE

Answer 1

a) 7^2x=7^6
2x=6
x=3
b) 3^(2x+3)=3^17
2x+3=17
2x=14
x=7
c) 2^3(2x+1)=2^21
6x+3=21
6x=18
x=3
d) 5^2(2x+3)=5^18
4x+6=18
4x=12
x=3
e) 2^2(3x-2)=2^14
6x-4=14
6x=18
x=3
f) 3^(2x+1)=260-17=243=3^5
2x+1=5
2x=4
x=2
5
a) 2^(x+2)<2^5
x+2<5
x<3⇒x={0,1,2}
b) x^4≤5^4
x≤5 ⇒x={0,1,2,3,4,5}
c)
3^(x+2)≤3^4
x+2≤4
x≤2 ⇒x={0,1,2}
d) 2.2^x.3^x≤72
2^x.3^x≤72:2
(2.3)^x≤6²
x≤2 ⇒x={0,1,2}
e) 3^(2x-1)<3^7
2x-1<7
2x<8
x<4⇒x={0,1,2,3}
f) 18^x.3^4.2^2:2^5≤3^10
18^x≤3^6.2^3
18^x≤18
x≤3 ⇒x={0,1,2,3}
g) 
2^(3x+2)≤2^8
3x+2≤8
3x≤6
x≤2 ⇒x={0,1,2}
h) 5^2(2x+1)≤5^18
4x+2≤18
4x≤16
x≤4
x={0,1,2,3,4}