Question

Rezolvati in Z urmatoarele inecuatii
a). 2x(x-6) + 9 mai mare sau egal x(x-6)
b). 2x(x+5) + 16 mai mare sau egal x(x+2)
c). (x+2)(x-2) > 10x - 29

Answer 1

a). 2x(x-6) + 9≥x(x-6) 
2x²-12x+9≥x²-6x
x²-6x+9≥0
(x-3)²≥0
(x-3)²=0
x₁,x₂=3

b). 2x(x+5) + 16≥ x(x+2)
2x²+10x+16≥x²+2x
x²+8x+16≥0
(x+4)²≥0
(x+4)²=0
x₁,x₂=-4

c). (x+2)(x-2) > 10x - 29
x²-4>10x-29
x²-10x+25>0
(x-5)²>0
(x-5)²=0
x₁,x₂=5