Question

ex.3,4,5 va rog dau funda si 30 de puncte

Answer 1

ex 3. 
a)
2x≤6
x≤6:2
x≤3 , x∈{0,1,2,3}
b)
4x≥8
x≥8:4
x≥2, x∈{2,3,4.......)
c) 
3x>9
x>9:3
x>3, x∈{4,5,6,....}
d)
20≥4x
4x≤20
x≤20:4
x≤5 , x∈{0,1,2,3,4,5}
e)
21<7x
7x>21
x>21:7
x>3, x∈{4,5,6,7.....}
f)
30≤5x
5x≥30
x≥30:5
x≥6, x∈{6,7,8,9,....}

ex.4
a)
x:3≥2
x≥3·2
x≥6, x∈{6,7,8,....}
b)
x:3≤1
x≤3·1
x≤3 , x∈{0,1,2,3}
c)
x:4<3
x<4·3
x<12, x∈{0,1,2,3,4,5,6,7,8,9,10,11}
d)
x:5≥8
x≥8·5
x≥40, x∈{40,41,42....)
e)
x:7<4
x<7·4
x<28, x∈{0,1,2,3,......27}
f)
x:6>5
x>6·5
x>30, x∈{31,32,....}

ex.5
a)
12:x<4
x>12:4
x>3, x∈{4,5,6.....}
b) 
14:x>2
x<14:2
x<7, x∈{0,1,2,3,4,5,6}
c)
15:x≤3
x≥15:3
x≥5, e∈{5,6,7,...}