Răspuns :
Răspuns:
a)7x+3 < 2x + 10 | -3 -2x
5x < 7 | :5
x < 7/5
b)2 -3x [tex]\geq[/tex] 4x -12 | +12 +3x
14 [tex]\geq[/tex] 7x | :7
2 [tex]\geq[/tex] x | x(-1)
x [tex]\leq[/tex] 2
c)5(3 -2x) [tex]\leq[/tex] 15
15 - 10x [tex]\leq[/tex] 15 | -15
-10x [tex]\leq[/tex] 0 | : (-10)
x [tex]\leq[/tex] 0
d)4(8-3x) > 12 -2x
32 -12x > 12 -2x | +12x -12
20 > 10x | :10
2 > x | x(-1)
x < 2
Spor la teme!
Răspuns:
a) 7x+3<2x+10 =7x-2x < 10-3 ⇒ 5x <7 ⇒ x <7/5
b) 2-3x ≥ 4x-12 = 3x+4x ≥ 12+2 ⇒ 7x ≥ 14 ⇒x ≥ 14/7≥ 2
c)5(3-2x)≤15 = 2x ≤ 15-15 ⇒2x ≤ 0⇒x ≤0
d)4(8-3x)>12-2x=2x+3x > 32-12 ⇒5x > 20 ⇒x > 20/5 > 4