Question

4)rezolvati in multimea numerelor reale inecuatiilor:
a)2(3x-1)≤10
b)3(2x+6) mai mare 12
c)3(5x+8) mai mare -6
d)6(1-4x)≥-18
e)7(1-2x) mai mare -140
f)-15 mai mare 5(3-4x)

Answer 1

a)2(3x-1)≤10
6x-2≤10
6x≤12
x≤2 
x∈[-∞,2]
b)3(2x+6) > 12
6x+18 > 12
6x > -6
x > -1

c)3(5x+8)> -6
15x+24> -6
15x> -30
x>-2

d)6(1-4x)≥-18
6-24x≥-18
24≥24x
1≥x
x≤1

e)7(1-2x)> -140
7-14x> -140
147>14x
x<147/14
x<21/2

f)-15 > 5(3-4x)
-15 > 15-20x
20x>30
x>3/2