Question

Rezolvati in N inecuatile:
A). 3(6-x) ≥ 15.
b). (2x - 2) 3 - 12 ≤ 24.
c). [( x-169 :13) 3 - 2] :7 ≤ 4.
d). 72 : ( x-3 ) > 9 si x : 5 ≥ 2.

Answer 1

a) 18 -3x $\geq$ 15
<=> -3x $\geq$ -3 => x $\geq$ 1 => x ∈ [1; ∞ ) 
b) 6x -6 -12 ≤ 24 
<=> 6x -18 ≤ 24
<=> 6x ≤ 42 => x ≤ 7 => x ∈ (-∞; 7]
c) [(x -13)*3 -2] :7 ≤ 4
<=> (3x -39 -2) :7 ≤ 4
<=> 3x -41 ≤ 28
<=> 3x ≤ 69 => x ≤ 23 => x∈ (-∞; 23]
d)72 : (x -3) > 9 
<=> x-3 > 648  => x > 651 => x∈(651; ∞)
e) x :5 ≥ 2 => x ≥ 10 
=> x∈ [10; ∞)