Question

19.Determinati numerele naturale care verifica inegalitatile:a)3(x-2) ≤ 3
b)(x+2)·3-45 ≤ 15
c)18x-14 ≥ 2 · (3x+5)
d)243:(x-4) > 9 si x : 5 ≥ 2
e)4x-1000 : 50 -620:4=5
f) (3·x+5·x):8=10
g)15·(36·x-12·x): 120=3
h)7·(15·x+35·x) : 10 + 2·x=185

Answer 1

b) (x+2)x3-45≤15
3x+6-45≤15
3x-39≤15
3x≤15-39
3x≤24
x≤24:3
x≤8

Answer 2

b)3x+6-45<=15
3x<=15+45-6
3x<=54
x<=54:3
x<=18
x∈(-ω;18]         ω=infinit
a)3(x-2)<=3
3x-6<=3
3x<=9
x<=9:3
x<=3
X∈(-ω;3)
C)18x-14>=6x+10
18x-6x>=10+14
12X>=24
x>=24:12
x>=2
x∈[2;+ω)
e)4x-1000:50-620:4=5
4x-20-155=5
4x=5+155+20
4x=180
x=180:4
x=45
F)(3x+5x):8=10
3x+5x=8*10
8x=80
x=80:8
x=10
g)15*24x:120=3
360x:120=3
3x=3
x=3:3
x=1
G)350x:10+2x=185
35x+2x=185
37x=185
x=185:37
x=5